A consecutive series of prison suicides in Scotland between 1970 and 1982 was examined. The initial phase of imprisonment was found to be the most vulnerable stage of confinement, with almost two-thirds of the deaths having taken place within the first month. A disproportionately high number were found to be on remand. A history of some form of psychiatric involvement was common, and a third of the group had received previous psychiatric inpatient treatment. In contrast to results from general population studies, there was little evidence to link suicide with a history of depressive illness. A record of problems with either alcohol or drug dependence was found in almost half the cases. The importance of general measures designed to reduce stress and promote coping mechanisms is emphasised.