People with a history of psychiatric disorder are at higher risk of suicide than people without such a history. The policy of reducing inpatient care in psychiatry has probably meant that some of the risk of suicide has shifted from the hospital to the community setting. We have quantified the risk of suicide within a year of psychiatric discharge in a population-based study in the Oxford health region, UK. We calculated suicide rates per 1000 person-years at risk (time from discharge to death, subsequent readmission, or the end of the study) and the standardised mortality ratio (SMR) for suicide, taking the value among the general population as 1. Among male patients the SMR for suicide (defined by coroner's verdict of suicide) in the first 28 days after discharge from inpatient care was 213 (95% CI 137-317); the equivalent SMR for female patients was 134 (67-240). The result was similar when we defined suicide more broadly as a suicide, open, or misadventure verdict. The suicide rate in the first 28 days after discharge was 7.1 (4.1-12) times higher for male patients and 3.0 (1.5-6.0) times higher for female patients than the rate during the remaining 48 weeks of the first year after discharge. Most of the patients studied (both those who committed suicide and those who did not) had been psychiatric inpatients for only a short time. The findings confirm that there is significant clustering of suicide soon after discharge from psychiatric care. Skilled support after discharge for high-risk patients in the community is essential. Audit of suicides that occur soon after discharge may help identify the patients at highest risk and thereby reduce the number of avoidable deaths.