Under the Misuse of Drugs Act 1977, the possession of a controlled drug for personal use is a criminal offence in Ireland, punishable by penalties up to and including imprisonment. The Act also confers on An Garda Síochána the power to stop and search individuals who – with reasonable cause – are suspected to be in possession of a controlled drug. Comprehensive analysis from jurisdictions worldwide has demonstrated that a criminal justice approach to tackling problematic drug use, including the criminalisation of possession of drugs for personal use, compounds the harm caused by these drugs. This report discusses why the current criminal justice approach in Ireland represents a failure of government policy and needs urgent reform. It argues in favour of decriminalisation of controlled substances for personal use as an essential component of a health-led approach to drug policy. It offers recommendations on repealing Section 3 of the Misuse of Drugs Act 1977 and other legal reforms that would help to embed an evidence-based approach to reform focused on health and harm reduction.