Can I drive after using medicinal cannabis in Queensland?
No. Under section 79(2AA) of the Transport Operations (Road Use Management) Act 1995 (Qld), it’s an offence to drive, attempt to drive, or be in charge of a vehicle while THC is present in your blood or saliva, full stop. The offence doesn’t ask whether you were impaired, and it doesn’t differentiate between legal prescriptions and non-legal sources. As at 9 July 2026, Queensland has no defence for medicinally prescribed cannabis in this offence, unlike some prescribed medications for other conditions.
If you’ve been charged with drug driving after using prescribed medicinal cannabis, contact us for confidential advice. We’re available 24/7 for urgent matters.
Why doesn’t a prescription help?
Queensland’s drug driving offence is a presence offence, not an impairment offence. The roadside saliva test and the laboratory analysis tests are only designed to detect whether a “relevant drug” is present at all, not how much, and not whether it’s affecting your driving. Because the law is written around presence rather than impairment, having a valid prescription and taking your medication exactly as directed doesn’t change whether the offence is made out; it can only be relevant to how a court deals with you (for example, in sentencing) once guilt is established.
This is different from some other prescribed medicines, where a driver who is affected but taking the medication as directed may have other options available. There’s no equivalent carve-out for THC under the current law.
What counts as a “relevant drug” for roadside testing?
The Act defines a “relevant drug” as a drug prescribed by regulation, and Queensland Police’s roadside saliva testing currently targets four: THC (the psychoactive component of cannabis), methylamphetamine, MDMA, and cocaine (added to the program in 2023). A positive roadside screen triggers a 24-hour licence suspension, and a notice to appear in court. The sample is sent for laboratory analysis and confirmation to prove the offence in court. See Queensland Police’s drug driving information for how the testing process works.
How long can THC stay detectable after use?
This is the practical trap for medicinal users. Unlike alcohol, THC can remain detectable in saliva for many hours after use, sometimes as long as weeks, and detection windows vary considerably between people depending on dose, frequency of use, and individual metabolism. Regular or higher-dose users can test positive well after any subjective effects have worn off. There’s no reliable “safe” waiting period you can count on, which is precisely why the presence-based offence catches people who genuinely believed they were fine to drive.
What are the penalties for driving with THC present?
Penalties escalate sharply if you have prior convictions for a drink or drug driving offence within the previous 5 years (figures are the maximum penalty; penalty unit value is $172.70 as at 1 July 2026):
| Offence | Legal basis | Maximum penalty |
|---|---|---|
| First offence | s 79(2AA) | 14 penalty units ($2,417.80) or 3 months’ imprisonment |
| One prior conviction within 5 years | s 79(2F) | 20 penalty units ($3,454.00) or 6 months’ imprisonment |
| Two prior convictions within 5 years | s 79(2G) | 28 penalty units ($4,835.60) or 9 months’ imprisonment |
A conviction also brings a licence disqualification on top of any fine or imprisonment. For most people that’s the part that really hurts, so it gets its own section.
How long will I lose my licence for?
On conviction the court must disqualify you from holding or obtaining a Queensland driver licence under s 86 of the Act. How long depends mainly on two things: the licence you held at the time, and your traffic history in the 5 years before conviction.
| Your situation at the time of the offence | Disqualification |
|---|---|
| First offence, holding an open licence | 1 to 9 months (s 86(2)(f)) |
| First offence, but you held a learner, probationary, provisional or restricted licence, were unlicensed, or were driving under a s 79E order | 3 to 9 months (s 86(2)(e)) |
| One prior drink or drug driving conviction within 5 years | 3 to 18 months (s 86(2B)) |
| More than one prior drink or drug driving conviction within 5 years | 6 months, automatic (s 86(2D)) |
| A prior conviction within 5 years for driving under the influence (s 79(1)) or dangerous driving | 9 months, automatic (s 86(2E)) |
| Priors in both of the above categories within 5 years | 1 year, automatic (s 86(2F)) |
Where the table gives a range, the court sets the exact period, and it must have regard to the test result and the danger, real or potential, to the public (s 86(2A)). Where the table says automatic, the disqualification flows from the conviction itself. A “s 79E order” is the order that lets some drivers keep driving while an earlier drink or drug driving charge is still before the court; offending while on one puts you in the 3-month-minimum bracket.
A valid prescription can’t move you between brackets, but a clean history and medication taken as directed are exactly the kind of circumstances that pull a first offence toward the bottom of its range rather than the top. Eligible drivers may also be able to apply for a work licence before the conviction is dealt with, which is often the difference between keeping and losing a job.
Is there any defence at all?
Generally, no. The Act does contain a narrow defence in s 79(6), sometimes called the “sleeping it off” defence, for someone who wasn’t actually driving: broadly, if you can show you’d deliberately taken yourself out of the driver’s seat (or stayed out of the vehicle entirely), and the vehicle was parked safely, a court must not convict. It has nothing to do with prescriptions; it’s about not having intended to drive at all. Beyond that, the strength of a defence usually turns on the testing procedure itself. The taking, storage and laboratory analysis of the specimen must follow the Act’s requirements, and irregularities there can be challenged.
What should I do if I’ve been charged?
Don’t assume a valid prescription will resolve the charge. It won’t, on its own. What it can do is support you at sentencing, and in some cases support an application for a work licence so you can keep driving for work while the matter is dealt with, depending on the charge and your history. Getting advice before your first court date matters: the test results, the way the sample was taken, and your own history can all affect how the charge is best handled.
Frequently asked questions
Does this apply to CBD-only products?
The offence targets THC specifically. CBD (cannabidiol) products genuinely free of THC aren’t caught by s 79(2AA), but many prescribed medicinal cannabis products, including oils and flower, do contain THC. Check with your prescribing doctor or pharmacist about what’s actually in your medication.
Can I be charged even if I only used cannabis the night before?
Yes. The offence is about presence, not impairment, and THC can remain detectable for many hours, sometimes longer for regular users. Timing your last dose the night before is not a reliable way to avoid a positive test.
Will I lose my licence immediately if I return a positive roadside test?
A positive roadside screen suspends your licence for 24 hours only. If you’re later charged with driving with a relevant drug present, your licence generally remains valid until the charge is dealt with by a court, unless you already have another drug driving charge pending. In that case it’s suspended immediately until your court date. Any disqualification imposed on conviction is separate and comes later.
Can I get a work licence for a drug driving charge?
Sometimes, depending on the specific charge and your driving history. See our work licence and special hardship order guide for the eligibility rules.
If you’ve been charged with drug driving after using medicinal cannabis, read about our approach to drink and drug driving charges or contact us for confidential advice. We’re available 24/7 for urgent matters.
This article is general legal information, not advice about your situation.
Worried about what happens next?
Speak confidentially with an experienced criminal defence lawyer. No judgement, no obligation. Available 24/7 for urgent matters.
