Foreigners from countries where marijuana is legal — the United States, Canada, Netherlands, Thailand — often ask: "It's legal at home. Why am I punished in Korea?" The answer: territorial principle. Korean law applies to anyone using or possessing drugs within Korean territory, regardless of nationality.
This guide explains the criminal and immigration procedures foreigners face in a drug case.
1. Korean Drug Law for Foreigners
Application Principle
The Narcotics Control Act applies:
- Territorial principle (속지주의) — anyone using/possessing within Korea is punished, foreigner or not.
- Personal principle (속인주의) — applies to Korean nationals using drugs abroad (not foreigners).
So smoking marijuana in Korea is punishable regardless of home-country legality. Even traces in urine/hair from prior overseas use can trigger violation if discovered post-entry.
Drug Categories (Korean classification)
- Narcotics: heroin, morphine, opium, cocaine
- Psychotropics: methamphetamine, MDMA, LSD, ketamine
- Marijuana: marijuana, hashish, cannabis oil
Medical-prescribed cannabis, CBD oil from abroad — can be treated as a narcotic upon entry to Korea.
2. How Conduct Is Treated
- Simple use, possession, habitual use, distribution/sale and smuggling are punished at different levels under the Narcotics Control Act, with distribution and smuggling punished most heavily. The actual sentence depends on the case.
- Each can lead to a deportation review and an entry ban (Immigration Act Articles 11 and 46). The disposition depends on the individual case.
A deportation review can follow even a single simple use, separately from the criminal outcome.
3. Immediate Action Checklist
Step 1. Deal with the criminal proceedings first
Drug cases require strong criminal defense; outcomes directly shape the offense review. Administrative scriveners cannot perform criminal defense.
Step 2. Surrender + cooperate
If pre-detection: voluntary surrender → mitigation. If detected: investigative cooperation (co-defendant info, surrender willingness) is mitigation.
Step 3. Enter treatment immediately
- Korea Anti-Drug Movement Headquarters (1899-0893)
- Specialist psychiatry + dependency assessment
- Treatment program completion certificate — critical for the review
Step 4. Begin offense-review preparation now
Run criminal track and review preparation in parallel.
4. Mitigation Evidence
Strong factors
- First detection + isolated incident
- Voluntary surrender / cooperation
- Voluntary treatment completion
- Low addiction (specialist diagnosis)
- Korean family (spouse, children)
- Long-term Korean residence + stable employment
- Risk in home country (political persecution etc.)
- Korean language proficiency + integration
Decisive risk factors
- Habitual use
- Distribution or recommendation to others
- Unregistered status (overstay)
- Other criminal record accumulation
- Drug-driven crime (theft, fraud combined)
5. Real Cases
Case A: Single marijuana use → Deportation
- 30s American male, E-7 visa
- Marijuana at friend's party; positive on random testing
- Criminal: 5M KRW fine
- Review: minimal documents
- Tone: "It's legal in the US, didn't think much"
- Result: Deportation + 5-year entry ban
Case B: Same offense → Status maintained
- 30s Canadian male, F-2-7 visa
- Same conduct, same criminal outcome
- Review documents:
- 6-month voluntary treatment completion
- 7 years in Korea, Korean spouse, child
- Korean company executive, ₩90M income
- Genuine remorse over reliance on home-country legality
- Coworker + spouse statements
- Tone: full responsibility + prevention + contribution
- Result: Status maintained + 1-year probation
The difference is not amount used — it's post-incident response quality.
6. Caution for Medical Cannabis Users
Even with home-country prescriptions:
- At Korean immigration: prescription presented → may still be confiscated and prosecuted
- CBD with any THC = treated as narcotic
- THC-0% CBD without Korean food/drug safety approval = also confiscated
Discontinue cannabis use during Korean stay; consult a Korean physician for alternatives.
7. Re-entry After a Drug Deportation
The entry-ban period is decided by the Ministry of Justice for each case (Immigration Act Article 11); distribution and smuggling cases are treated most strictly.
Applications to lift a ban can be filed, but drug cases are reviewed strictly. Factors considered include:
- Time elapsed since departure
- Stable home-country social life
- Justified re-entry purpose (Korean family etc.)
- Strong sponsorship
Even with these factors, the result depends on the individual review.
8. Sunshine's Drug-Case Protocol
4-step package
- Initial consultation (same day) — risk assessment
- Offense-review document collection (10–14 days) — treatment, family, employment
- Office attendance support (day-of) — translation, supplemental statement
- Post-decision follow-up (30 days)
The office handles only the administrative offense review. We do not handle litigation or court representation, including criminal defense (outside the scope of an administrative scrivener).
9. Time Is Critical
In drug cases, timing matters. Voluntary surrender, treatment enrollment, and review preparation must start simultaneously. Beginning after the criminal case closes can leave less time to prepare mitigation.
Initial consultation — Korean, English, Chinese, Japanese, Vietnamese — confidential.
Related articles: