This chapter the body of legislation directly or indirectly relevant to the control of drugs, beginning with the Poisons (Ireland) Act, 1870 and concluding with the Criminal Justice (Theft and Fraud Offences) Bill, 2000. Commentary on some of the implications of the most recent changes in legislation is provided. The organisation of the enforcement agencies and their interrelationships are presented. This is followed by an overview of the processes involved in drug law enforcement, up to procedures for sentencing. Finally, some recent developments in activities in the law enforcement area, related to both supply and demand reduction are summarised.