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Medicinal Cannabis & Driving in SA: Law, Penalties & Reform (2026)
Strict presence offence — parliamentary committee has recommended reform Last verified:
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- : Verification sweep: legal position checked against legislation, official guidance and practitioner sources; figures current as at July 2026.
SA's official driver guidance states police conduct random roadside saliva tests for THC, methylamphetamine, cocaine and MDMA, and — unlike drink driving's concentration thresholds — the presence of any amount of these drugs is an offence. Refusing or failing to comply with drug testing is itself an offence, can mean immediate loss of licence at the roadside, and carries disqualification of at least 12 months on conviction. A parliamentary committee has recommended amending the Road Traffic Act so unimpaired prescribed patients would not commit an offence, but this is a recommendation only — not passed law.
Just tested positive? What happens next in South Australia, step by step →
Medicinal cannabis and driving in SA: where the law stands
South Australia's official driver guidance is blunt: police conduct random roadside saliva tests for THC, methylamphetamine, cocaine and MDMA, and — unlike drink driving, where a prescribed alcohol concentration must be reached — the presence of any amount of these drugs is an offence. A prescription does not change that under current law.
A prescription authorises possession and use of the medicine dispensed to you. It does not change the driving offence, because the offence is presence, not impairment.
Is medicinal cannabis legal in South Australia?
Yes — medicinal cannabis can be lawfully prescribed, possessed and used in SA with a valid prescription. Recreational cannabis remains illegal.
For prescribed drivers, the point is that the *legality of your medicine* does not extend to the road: SA treats the presence of any amount of THC as an offence, with no threshold below which you are safe, and no prescription defence. That is exactly what the parliamentary committee (below) has recommended changing.
What happens at a roadside test today
Roadside drug testing in SA follows the national pattern. See our guide, Mobile Drug Testing (MDT) in Australia, for the full process. In brief:
- The stop. You can be tested at a static site or by a mobile patrol. You must stop and comply with a lawful direction to test — refusing the oral fluid test is itself a serious offence.
- The screening swab. A saliva swab screens for THC, methylamphetamine, cocaine and MDMA. It does not measure impairment, dose, or when you took your medicine.
- The second test. A positive screen leads to a second oral fluid sample on more sensitive equipment. Many first-positives end here when the second test disagrees.
- The driving ban. After a confirmed positive you will be banned from driving for a period — commonly 24 hours. Driving within the ban is a separate offence.
- Laboratory confirmation. The roadside result is indicative only. Charges typically follow laboratory confirmation, which can take weeks.
Refusing or failing to comply with a drug screening test, oral fluid analysis or blood test is itself an offence, can mean immediate loss of licence at the roadside, and carries disqualification for at least 12 months on conviction.
The key point for a prescribed patient: a roadside test detects the *presence* of THC, which correlates poorly with both impairment and time since dose. You can test positive many hours after your last dose, long after any impairing effect has passed. Under SA law, detection is enough.
Penalties
What a first offence costs: SA offers an expiation pathway — $875 (as at 1 July 2025) with a 3-month licence disqualification. Prosecuted at court instead: a fine of $900–$1,300 and mandatory disqualification of at least 6 months. Expiation avoids a conviction; court doesn't necessarily.
Amounts are re-indexed annually — re-check the Legal Services Commission of SA before relying on a figure.
What this means in practice
If you are a prescribed patient in SA, the honest position is:
- A valid prescription is not a defence. The offence is made out by the presence of any amount of THC. The question is whether THC was detected, not whether you were impaired.
- Keep your prescription and dispensing records accessible. They will not prevent a charge in SA, but they matter later — for court and for the reform argument.
- Never drive impaired. Every discretion and proposed reform evaporates if you are impaired, and it is dangerous.
- If you test positive, see our step-by-step guide, "Tested positive in SA: what happens next", and get legal advice early.
Reform status: a committee says change it — Parliament hasn't yet
The Joint Committee on the Legalisation of Medicinal Cannabis tabled its interim report on 25 September 2024. Recommendation 1 calls on the Minister for Infrastructure and Transport to draft Road Traffic Act amendments so that it would not be an offence for a prescribed medicinal cannabis patient to drive with THC present, provided the medicine is used in accordance with the prescription — explicitly the Tasmanian model — with community consultation on the draft. This is a recommendation, not law: as at July 2026 no government response or amending bill has been identified. Follow it on our Reform Tracker.
Common questions
Does any amount of THC really count in SA? Yes — SA's official guidance states presence of any amount of the tested drugs is an offence, with no minimum threshold.
Is medicinal cannabis legal in SA? Yes, with a valid prescription — but that does not make driving with THC present lawful. SA is a presence-offence state with no prescription defence.
Didn't SA recommend fixing this? A parliamentary committee recommended an unimpaired-patient exemption, but a recommendation only becomes protection when Parliament passes it. It hasn't.
Active reform items
- Joint Committee on the Legalisation of Medicinal Cannabis — interim report (tabled 25 September 2024, 13 recommendations). Recommendation 1: Minister for Infrastructure and Transport to draft Road Traffic Act amendments so it is not an offence for a prescribed patient using THC medicine per prescription to drive with THC present (Tasmanian model), with community consultation on the draft. (Committee recommendation only — no government response or bill identified.)
Quick answers for South Australia
Can I drive with a medicinal cannabis prescription in South Australia?
SA's official driver guidance states police conduct random roadside saliva tests for THC, methylamphetamine, cocaine and MDMA, and — unlike drink driving's concentration thresholds — the presence of any amount of these drugs is an offence. Refusing or failing to comply with drug testing is itself an offence, can mean immediate loss of licence at the roadside, and carries disqualification of at least 12 months on conviction. A parliamentary committee has recommended amending the Road Traffic Act so unimpaired prescribed patients would not commit an offence, but this is a recommendation only — not passed law.
Is a valid prescription a defence to drug driving in South Australia?
No. In South Australia, driving with detectable THC is an offence regardless of a valid prescription. Driving while impaired is a separate, more serious offence everywhere in Australia.
What happens if I test positive at a roadside drug test in South Australia?
You will be unable to drive for a period while your sample goes to a laboratory, and charges typically follow laboratory confirmation. See our step-by-step guide, “Tested positive in South Australia: what happens next”, and get legal advice early.
What is the penalty for drug driving in South Australia?
As at 1 July 2025 (LSC SA): first presence offence expiation $875 with 3-month licence disqualification; prosecuted at court, fine $900–$1,300 with mandatory disqualification of at least 6 months. Refusal: immediate roadside loss of licence possible, disqualification of at least 12 months on conviction. Amounts re-index annually — re-check lsc.sa.gov.au.
How long does THC stay detectable after use, and does it matter in South Australia?
Detection windows depend on how often and how much you use, and on the test used. Our guide “How long does THC stay detectable” explains the windows for oral fluid, blood and urine. What matters for a charge is whether THC is present at the time of driving, not when you last used.
Primary sources for this page
- https://www.mylicence.sa.gov.au/road-rules/the-drivers-handbook/drugs
- https://www.legislation.sa.gov.au (Road Traffic Act 1961)