A cannabis DUI is a criminal charge. But THC tests are often weak evidence, and the traffic stop itself can be challenged.
Here is a common story. A routine traffic stop turns into a DUI arrest because the officer says they smell cannabis. Next, you are asked to take a blood or urine test.
Here is another. Police suspect drunk driving, but you blow under .08 on the breath test. Instead of letting you go, they switch and say you might be high.
Cannabis is legal in Illinois for medical and adult use. That does not make it legal to smoke in your car or to drive while impaired. Cannabis in a car must also be in a sealed, odor-proof, child-resistant container.
Many drivers charged with a cannabis DUI have real defenses. Others can lower the damage to their record and license. Driver Defense Team defends marijuana DUI cases from Chicago and Villa Park in Cook, DuPage, Kane, Lake, and Will County courts. Free case review: (312) 487-4700.
When can you be charged with a marijuana DUI?
Like alcohol, cannabis has a legal limit in Illinois. You can be charged if, within two hours of driving, a test shows:
- 5 nanograms or more of THC per milliliter of whole blood, or
- 10 nanograms or more of THC per milliliter of another body fluid, such as saliva or urine
Police get these numbers from a blood, saliva, or urine test after arrest.
You can also be charged without a test result. The officer may point to signs of impairment, such as:
- The smell of cannabis
- Bloodshot or dilated eyes
- A fast pulse
- Trouble with memory or field sobriety tests
What are the penalties for a marijuana DUI in Illinois?
The penalties are the same as for an alcohol DUI. A first-offense cannabis DUI is usually a Class A misdemeanor. If convicted, you face:
- Up to one year in jail
- A fine of up to $2,500, plus court costs
- Loss (revocation) of your driver’s license for at least one year
- A drug and alcohol evaluation, risk education classes, and possibly treatment
Some first offenders can get court supervision instead of a conviction. If you finish the court’s terms, no conviction is entered. In Illinois, you can get DUI supervision only once in your life.
Some cases are charged as aggravated DUI, which is a felony. See our felony DUI page.
Your license can be suspended before your court case ends
A cannabis DUI arrest can also trigger a statutory summary suspension of your license. This is separate from the criminal case.
For most first offenders:
- Failed test: 6-month suspension
- Refused test: 12-month suspension
The suspension starts on the 46th day after you get the notice. You have 90 days from the notice to ask for a hearing to challenge it. Do not wait. If you act early, we may be able to challenge the suspension before it starts.
Defenses to a cannabis DUI
The right defense depends on why you were stopped and what happened after. Common defenses include:
1. The THC test does not prove you were high. THC can show up in blood and urine days or even weeks after use. People who use cannabis often may always have some THC in their system, high or not. There is no test that truly measures how impaired a driver was from cannabis.
2. The traffic stop was not legal. Police need a valid reason to pull you over. If they did not have one, the evidence from the stop may be thrown out.
3. The officer’s observations are weak. Red eyes, a fast pulse, or nerves can have other causes — like being tired or scared. We test the officer’s story against the video and reports.
We get every piece of evidence in your case. Then we check it for gaps, mistakes, and broken procedures.
Why choose Driver Defense Team?
We focus on driving cases — DUIs, license problems, and traffic tickets. We have handled thousands of them. We know the local courts, prosecutors, and judges, and which defenses work.
Your GamePlan. Every case is different. We build a defense plan around your facts and your goals, and we adjust it as the case moves.
A team, not just one lawyer. You get our DUI team and a case manager. You will never go two weeks without an update. We call before and after each court date so you know what to expect and what happened.
Help in your language. Our team speaks English, Spanish, and Polish.
Court dates. A DUI is a criminal case. You must appear for your criminal court dates — in person, or by Zoom only if that court allows Zoom for that date. We prepare you for each one and stand with you.
How we work your case
- Free case review. We learn what happened and what matters most to you.
- Evidence review. We get the police reports, test results, and video, and look for weak points.
- License fight. We look at challenging the summary suspension so you can keep driving.
- Plan and prep. We build your GamePlan. If it helps, we point you to an evaluator or treatment early to show the court you took action.
- Court. We fight for the best result — dismissal, a reduced charge, supervision, or a win at hearing or trial.
- After the case. We help with what comes next, like getting your license back.
Cannabis DUI FAQs
How is a marijuana DUI different from an alcohol DUI in Illinois?
The law is the same. Both fall under the same DUI statute (625 ILCS 5/11-501). Both are usually Class A misdemeanors for a first offense, and both can become felonies.
The big difference is proof. There is no breath test for cannabis. Police must use blood, saliva, or urine tests, and those tests show THC that may be left over from days ago. That gives us more room to fight.
What if I am a registered medical cannabis patient?
A medical card does not stop a DUI charge. But Illinois law treats card holders differently on the THC limit. For a registered patient, a THC number alone is usually not enough — the state must show you were actually impaired.
That means the case often turns on your driving and how you acted during the stop. We can challenge the officer’s claims in court. Tell your lawyer about your card and how you use cannabis.
Can I be arrested for DUI if I used cannabis days ago?
Yes. THC can stay in your body long after the high is gone. You could be sober, get stopped for a small violation, and still be arrested.
That is also why these cases are often defensible. A test shows you used cannabis at some point — not that you were impaired when you drove. We look at whether the stop was legal and whether any signs of impairment have another explanation.
Talk to a cannabis DUI lawyer today
A cannabis DUI can cost you your license, your record, and your job. You do not have to face it alone. See our Illinois DUI defense hub and first offense DUI page, or call for a free case review: (312) 487-4700 · Chicago and Villa Park · Cook, DuPage, Kane, Lake, and Will.
