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At the Crossroads of Cannabis and Business

Cannabis industry legal planning, regulatory support, corporate guidance, and compliance strategies

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A Trusted Guide for Cannabis Businesses

Our cannabis lawyers have a long history of providing cannabis businesses and related parties with the legal planning, regulatory support, corporate guidance, and compliance strategies they need.

Since 2010, we’ve been helping businesses, investors, governments, and others navigate rapidly evolving cannabis regulations and policy. Our cannabis lawyers help cannabis businesses with their corporate legal matters involving company formation and structuring, transactional agreements, M&A, IPcorporate governance, taxation, licensing, and the acquisition and leasing of real property.

With over a decade of multi-state experience in the nation’s fastest-growing medical and adult-use cannabis markets, you won’t find a more experienced and reputable cannabis law team than Harris Sliwoski, anywhere. Our cannabis attorneys serve the exacting needs of our clients based in Arizona, CaliforniaWashington, and Oregon, and elsewhere in this complex, fascinating, and ever-changing industry.

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Cannabis Businesses Attorneys in Arizona, California, Washington, and Oregon

Harris Sliwoski’s cannabis business attorneys are recognized national leaders at the forefront of the cannabis industry. Even before legalization, our cannabis lawyers were helping educate would-be cannabis operators, state and city council representatives, and an anxious public.

With legalization, our well-established Corporate Law practice, our deep knowledge of cannabis regulation and our extensive industry and regulatory network uniquely positioned us to build a robust and client-centered cannabis law practice. We’ve designed this practice to meet the unique needs, challenges, and opportunities of our expansive network of cannabis clients:  retailers, distributors, processors, manufacturers, growers, investors, and our hundreds of ancillary business clients, that are the future of a strong, sustainable cannabis industry.

Our cannabis law practice has stood the test of time, while our commitment to our clients has always remained: we help people build the durable business and legal frameworks they need for long-term growth and success.

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Serving U.S. and International Cannabis Clients

As a global cannabis law firm with referral and partnership networks around the world, Harris Sliwoski represents businesses at nearly every level of the cannabis supply chain. Our legal team has years of combined experience advising clients based in the United States and other countries worldwide. We have done it all.

Our reputation as a global leader in the cannabis industry reflects our commitment to what this industry can and will become. Our team works on issues related to hemp and cannabis across disciplines and territories. Harris Sliwoski attorneys are committed to conducting presentations at national and international conferences, publishing a large number of useful articles, and providing the public with the latest news and updates through our acclaimed Canna Law Blog.

Full-Service Legal Planning for
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Get in Touch with Our Cannabis Law Team

Get started by filling out the form, or call 1-888-330-0010 to schedule an initial consultation.

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Our Clients' Successes

“Harris Sliwoski expertly guided us through the formation of our company. They continue to assist with necessary registrations and compliance with numerous regulations. They were able to promptly answer all our many questions and provide understandable options, explanations and practical advice. We expect to continue to use Harris Sliwoski on a regular basis as our company expands. They were also able to introduce us other professional experts. We would not hesitate to recommend Harris Sliwoski to any companies in need of legal advice.”

user icon Three Continents Foods LLC

This law firm was a huge help as our company went through the process of commercial licensing in the California cannabis industry.  They have helped us with a variety of legal issues in a timely fashion, while clearly communicating with us throughout the process.  Everyone we’ve worked with at Harris Sliwoski is an expert in their field and we have always felt that we were in good hands through our legal representation.

user icon Wil Crummer, CEO PRO Farms

Legal stuff is always scary. And I’ve had to play offense a couple times, begrudgingly. To have Harris Sliwoski have my back? It made things a lot less prickly. They quickly walked me through my options, and were refreshingly consistent in their communications, timing and billing. I’ve been lucky to stay out of the legal side of things my whole career, thankfully. When things went a little wrong, Harris Sliwoski quickly made things right.

user icon Aaron Draplin, Founder Draplin Design Co.

I am impressed with this law firm. They answered all my questions regarding cannabis businesses and the California cannabis framework, and they have helped me with a variety of legal issues in a timely fashion, while always clearly communicating with us throughout the process. They also redirected me to other quality people for my business needs. Everyone I worked with at Harris Sliwoski is an expert in their field, and I was in good hands throughout my legal representation.

user icon Corey T., CEO Thinc Cubed, LLC

I have been working with the lawyers at Harris Sliwoski for more than 20 years both as a business owner and as an executive at a large east-coast health system and that is because they have always efficiently provided high level and clear international law advice. Most recently, Harris Sliwoski provided legal support on many matters related to procuring medical products worldwide. Their support was particularly helpful to during the onset of COVID, when there was a big need for securing PPE quickly, all while navigating complicated international and domestic legal requirements. Harris Sliwoski’s team of international lawyers helped by conducting rapid-fire due diligence on potential suppliers, navigating the legal logistics for getting product from overseas and through U.S. customs, and drafting contracts to protect against various sorts of horribles. They did this by essentially providing what amounted to 24/7 service. I cannot recommend them highly enough.

user icon Dan Pak Hospital Supply Chain Executive

Harris Sliwoski has represented our company in the legal cannabis industry for years. Harris Sliwoski has advised us in a wide variety of legal matters, and they are truly experts in their field. I would highly recommend Harris Sliwoski to anyone with questions about cannabis law, or any legal matters. They have been great for our Company, and will continue to guide us as our industry evolves

user icon Matt Hurt, COO Cannabis Nation

You won’t find a better partner than Harris Sliwoski when trying to navigate the complex world of healthcare regulations.  They not only give sound and reliable legal advice, but they are also very responsive and are able to guide you in a way that helps you reach your business objectives as well.

user icon Joseph Axelrod, General Counsel Irwin Naturals

When we started the process of building a ‘seed to sale’ cannabis company in Oregon, we saw the need for expert legal counsel.  The cannabis sector is fraught with potential peril at every turn, and we wanted the best legal advice we could find.  After talking to several firms and individuals, we feel extremely fortunate to have chosen Harris Sliwoski as our legal counsel.

user icon Tony Theiss, CEO and Co-Founder Redbarn Cannabis 

We use Harris Sliwoski on all our international legal matters, including on our international litigation matters. We have over the last few years been involved in a couple big international legal disputes and Harris Sliwoski’s international dispute resolution team provided us with expert legal assistance on both matters. They were always very careful to explain to us what they were doing and why and what their actions would likely cost us in legal fees. Most importantly, we did extremely well on both cases and I have no doubt Harris Sliwoski was a big factor in that.

user icon Kevin English, CEO We Are Camp

We have used Harris Sliwoski for legal help related to our international manufacturing. The lawyers with whom I worked had extensive familiarity with the international legal issues involved in our various projects and offered us key insights. I particularly appreciated how they always quickly and efficiently do what they say they will do and always within their cost estimates.

user icon Andrea Barona Valladolid, Senior Legal Counsel Fairphone

Tough Market, Bold Lawyers

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An intelligent, timely resource for the cannabis industry

Beyond advising and advocating for individual clients, our cannabis attorneys are committed to fortifying, defending, and building credibility for the industry as a whole. Harris Sliwoski’s cannabis business lawyers are more than legal strategists—they are thought leaders: forward-thinking bloggers, educators, writers, and speakers.

Our cannabis business lawyers regularly write articles for legal journals and frequently post to our acclaimed and widely followed Canna Law Blog. We speak to business and trade groups, academic institutions, and government bodies on a variety of cannabis legal issues, and our cannabis lawyers are frequently quoted by global, national, and local media outlets. We also have compiled a living Cannabis Glossary, to help with industry terminology. 

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A Decade of Leadership


Begin representing cannabis business clients in Washington under then-existing medical cannabis laws.


Begin representing cannabis business clients in Oregon under then-existing medical cannabis laws.


Expand into the California cannabis market and represent cannabis non-profits pursuant to the Compassionate Use Act of 1996 and the Medical Marijuana Patient Protection Act.


Launch the Canna Law Blog.


Assist multiple financial institutions in complying with the 2014 Financial Crimes Enforcement Network Guidelines regarding banking state-licensed cannabis companies.


Host first ever nationwide tribal cannabis conference at the Tulalip Resort and Casino with more than 800 people and more than 400 tribal council authorities in attendance.


Secure first ruling from the Washington State Bar Association holding that lawyers may ethically represent cannabis businesses.


Harris Sliwoski is appointed to the initial Oregon Liquor Control Commission Rulemaking Advisory Committee for pending adult use marijuana program.


Harris Sliwoski opens Portland, Oregon office.


Vince Sliwoski teaches a cannabis law course at Lewis & Clark Law School – among the first such courses offered in the nation.


Harris Sliwoski begins informal advisory relationship with Office of Earl Blumenauer (D- Oregon) regarding federal cannabis legalization issues and strategy.


Harris Sliwoski is retained by the National Credit Union Administration to provide advice and guidance regarding banking cannabis and hemp customers.


Harris Sliwoski launches its ketamine practice group.


Vince Sliwoski named in Chambers 2021 Guide for the first of several years

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