A national sample of suicides or suspected suicides by current prisoners was identified from the records held by the Safer Custody Group. Two questionnaires were sent to the prison where the death occurred. One was sent to the prison governor, the second to the prison medical officer. If a psychiatrist had assessed the prisoner, a third questionnaire was sent to him/her. The sample was a 2-year consecutive case series, defined by date of death. The time period covered was from January 1999 to December 2000. Results show that 172 suicides occurred among prisoners; 12 prisons, including 2 young offender institutions, had five or more suicides. The 172 deaths included 5 in the care of the Prison Escort Custody Service. Ninety-two percent of the suicides were by hanging or self-strangulation. The most common ligature points were window bars; the most common ligatures were bedclothes. Eleven percent of the suicides occurred within 24 hours of reception into prison; 32 percent occurred within 7 days. Forty-nine percent of the individuals were on remand. Eleven percent of the individuals were on a vulnerable persons unit. Sixty-three percent were located in single cells (including 9 percent that were in a segregation unit); of those in double cells, the cellmate was absent in around half. Ninety-two percent of the individuals were male; the proportion of females was highest (14 percent) in suicides aged 21 and under. Eleven percent were from an ethnic minority. Twenty-six percent had been charged with or convicted of a violent offense. In 6 percent of the cases, the offense was murder or manslaughter; six of these were serving life sentences. There is a need for a number of changes to prison health care services, and prison regime and environment based on these findings. Recommendations include reviewing prison cells and wards for potential ligature points; obtaining information on prisoners with mental health service contact within 24 hours of commitment; and training all prison officers in suicide prevention and risk. 10 tables, 23 figures, 10 references