Positive saliva drug test in Belgium: your rights at a roadside drug check

A positive saliva drug test at the roadside takes only a moment, but what happens next decides your case. Many drivers assume that a positive test is as good as a conviction. It is not: the saliva test is only an indication, the evidence comes from the laboratory — and that laboratory works with statutory thresholds.

How does a roadside drug check work in Belgium?

1. The standardised checklist. The police first look for signs of recent drug use using a checklist whose model is laid down by royal decree (Article 61bis of the Road Traffic Act – Wegverkeerswet / loi relative à la police de la circulation routière). Only if that checklist gives an indication may the saliva test follow. After a road accident, however, the saliva test may be taken straight away.
2. The saliva test. It only counts above set concentrations: 25 ng/ml for THC, 50 for amphetamine and MDMA, 20 for cocaine or benzoylecgonine and 10 for morphine or 6-acetylmorphine (Article 61bis § 2). Below those levels, the result is disregarded.
3. The laboratory saliva analysis. If the test is positive, a saliva analysis follows — not automatically a blood test, as is often assumed. The analysis only counts from 10 ng/ml THC, 25 ng/ml amphetamine and MDMA, 10 ng/ml cocaine or benzoylecgonine and 5 ng/ml morphine (Article 62ter § 1).
4. The blood test. This only comes into play when neither a saliva test nor a saliva analysis is possible. The thresholds are different: 1 ng/ml for THC, 25 for amphetamine and MDMA, 25 for cocaine or benzoylecgonine and 10 for free morphine (Article 63 § 2).

The law therefore sets thresholds for each substance and each analysis method. What is punishable is not the mere presence of a substance, but a concentration that reaches the statutory threshold. The prosecution then does not have to prove that you were actually impaired. With cannabis, traces of which can remain detectable long after use, that threshold is therefore often the turning point of the case.

Positive saliva drug test: what penalties do you face?

Drug driving is an offence tried by the police court (politierechtbank / tribunal de police). For offences committed on or after 1 September 2026, the penalty levels of the new Criminal Code apply.

• A fine of €2,000 to €20,000 (Article 37bis § 1 of the Road Traffic Act), surcharge multiplier (opdeciemen / décimes additionnels) included: the Act states €1,600 to €16,000, to be multiplied by 1.25. This is a level 1 penalty: imprisonment is ruled out. Instead of the fine, the court may also impose community service of 20 to 120 hours, a probation order of 6 to 12 months or a conviction by declaration of guilt (Article 36 of the Criminal Code). Court costs come on top.
• Offences committed before 1 September 2026 remain subject to the former rules: a fine of €200 to €2,000 plus the surcharge multiplier, with no prison sentence for a first offence. In practice, that means €1,600 to €16,000 for offences before 1 February 2026 and €2,000 to €20,000 for offences from 1 February to 31 August 2026 inclusive. The new rules apply to older offences only if they are more lenient (Article 2 of the Criminal Code).
• A driving ban (verval van het recht tot sturen / déchéance du droit de conduire) of eight days to five years — possible, not mandatory (Article 38 § 1).
• Reinstatement tests (herstelexamens / examens de réintégration): the court may make the return of your licence conditional on a theory and practical test and a medical and psychological examination. If, within three years of a conviction for one of the serious traffic offences listed in the Act, including drug driving, you commit another such offence, a driving ban of at least three months and reinstatement tests are mandatory (Article 38 § 6).
• Repeat offences. If, within three years of a conviction for drug driving, alcohol intoxication from 0.35 mg/l or drunkenness, you commit one of those offences again, you face a level 2 penalty — including imprisonment of six months to three years — with a fine of €4,000 to €50,000 (Article 36 of the Road Traffic Act). A further repeat offence within three years of the second conviction may lead to a level 3 penalty, with a fine of €8,000 to €100,000. For offences committed before 1 September 2026, a repeat offence carried imprisonment of one month to two years.

Twelve-hour driving prohibition and withdrawal of your licence

After a positive saliva test, a refusal, or where the checklist shows signs and no test was possible, a temporary twelve-hour driving prohibition applies (Article 61ter). This is a safety measure, not a penalty, but driving during those twelve hours is a separate offence (Article 37bis).

In addition, the public prosecutor may have your driving licence withdrawn immediately (Article 55 of the Road Traffic Act). This immediate withdrawal (onmiddellijke intrekking / retrait immédiat) in principle lasts fifteen days; the police court may extend it by up to three months (Article 55bis).

What if you refuse?

Anyone who refuses without a legitimate reason to undergo the saliva test, the saliva analysis or the blood test faces the same penalties as for a positive analysis (Article 37bis). Refusing therefore gains you nothing.

Defending a positive saliva drug test

• The checklist. Was it actually carried out and completed before the saliva test? Without an indication of recent use, there is as a rule no legal basis for the test, except after an accident. An irregularity does not, however, automatically lead to the evidence being excluded (Article 32 of the Preliminary Title of the Code of Criminal Procedure).
• The concentrations. Do the measured values really reach the statutory threshold for the method used? The test threshold (25 ng/ml THC) and the analysis threshold (10 ng/ml) are sometimes confused in practice.
• The sample. Was it correctly taken, sealed, stored and sent in time to an approved laboratory?
• The counter-analysis. You can have a second saliva analysis carried out by an approved laboratory at your own expense (Article 62ter). The time limit for this is short — which is the main reason to consult a lawyer immediately after the check.
• Prescription medicines. If you take morphine or amphetamine-type medicines on prescription, you should be able to prove it with the prescription. That does not automatically change the legal classification, but it does weigh on the sentence and sometimes on the assessment of your fitness to drive.

Even when the concentrations are established, the defence still influences the sentence. With your consent, the court may order a suspension of sentence (opschorting / suspension du prononcé, Article 64 of the Criminal Code) or grant a suspended sentence (uitstel / sursis), including for the driving ban (Article 65 of the Criminal Code), although at least eight days of a driving ban must actually be served (Article 41 of the Road Traffic Act). It takes your financial means into account and, if your situation is precarious, may go below the minimum fine (Article 52 § 2 of the Criminal Code). Read more in our article on suspension, suspended sentences and community service.

Ketamine and driving

In May 2026, the Chamber passed the law that expressly adds ketamine to the prohibited substances in Article 37bis (Act of 25 May 2026); this change only enters into force on a date to be set by the King. Until then, ketamine use at the wheel can as a rule only be prosecuted as drunkenness or a similar state (Article 35). The saliva tests used by the police cannot yet detect ketamine. Ketamine cases today therefore often rest on outward signs, which makes them vulnerable in terms of evidence.

Novex Advocaten can help

Did you test positive and are you waiting for the analysis? Or have you already received a summons (dagvaarding / citation)? Have your file reviewed before the hearing — the time limit for a counter-analysis runs out quickly. See also how we work as a drug driving lawyer in Brussels.

Call 0484 99 22 72 or email asfour@novexadvocaten.be.