The paper presents the results of a retrospective, self-report survey of pre-arrest drug use in a representative sample of 1751 men serving a prison sentence. Reported drugs used were cannabis (34%), opiates (9%), amphetamine (9%) and cocaine (5%), including 1% 'crack' users. Pre-arrest injecting was reported by 11% of inmates, including 68% of all opiate users and 57% of amphetamine users. Drug dependence was reported by 11%, including 7% dependent on opiates, 2% on amphetamines and 1% on cocaine. Relative to other drugs, the figure for cocaine is higher than is suggested by a previous clinic survey. Pre-arrest cannabis use was reported by 54% of black prisoners and 34% of white. White prisoners are more likely to report use of 'hard' drugs, drug dependence and injecting, but this masks a higher rate of cocaine use by black prisoners. Opiate use varied between health regions, from 3% of prisoners in the West Midlands to 25% of those from the Mersey region. These findings have implications for service provision and for an understanding of cultural influences on illicit drug use.