Self-poisoning is a common reason for admission to hospital; and, although most patients admitted do not have a psychiatric disorder, as a group they are at greatly increased risk of completed suicide. Admissions to a hospital in Central London over a four-year period were examined with special attention to patients admitted more than once. From 1991 to 1994 admissions for self-poisoning rose by 108%, with larger increases in the younger age groups of both sexes. 9% of patients were admitted more than once, the mean interval to repetition being three months. A third of the repeaters were readmitted within one month. The increase in admissions for self-poisoning, which has been noted elsewhere in the UK, is unlikely to be due wholly to changes in clinical practice. In view of the relation between parasuicide and suicide, further research and analysis is urgently needed.