Drug possession, distribution and sale as well as the publishing of information about drugs are regulated by Law no. 139/1998 and subsequent amendments (300/2005, 43/2011, etc.). In general, Slovak drug law is very strict and forbids possession, distribution, sale or publishing of drug-related information except by or for those with appropriate licenses.

There are three schedules of drugs and one table of precursors. Schedule 1 contain typically illicit substances like heroin, cannabis and LSD. Schedules 2 and 3 define drugs available by prescription and the rules that determine their availability. The penalties for possession are equalized, so for example, being in possession of a benzodiazepine without a prescription warrants the same penalty as possession of personal-use amounts of heroin. The law differentiates between possession for personal use and for sale. Personal use is further differentiated to "maximum of three standard daily doses" and "up to ten standard daily doses". However a "standard daily dose" is not defined by law and is determined on a case by case basis, often in favor of greater potential penalties. For example, law enforcement may consider one gram of cocaine as constituting more doses than users would.

Penalties specified in Drug Law no. 300/2005, § 171-174 include:

• up to 3 years for possession for personal use (up to three times standard daily dose)
• up to 5 years for possession for personal use in higher amounts (up to 10x standard daily dose)
• 4-10 years for possession, sale, distribution, importing and exporting (with such a charge probation is not possible, i.e. a person convicted of a crime at this level will go to jail)
• 1-5 years for "spreading toxicomania", which means distributing information that could "lead to drug abuse" (an example would be a blog expressing a favorable opinion of cannabis). While the law against "spreading toxicomania" is not typically enforced, it has the potential to harm free speech.
• 3-8 years if a drug crime is committed "in public" or to a minor