Background: Deliberate self-harm (DSH) is the strongest risk factor for future suicide. Up-to-date information on the extent of risk is lacking.

Aims: To investigate the risk of suicide after DSH during a long follow-up period.

Method: A mortality follow-up study to 2000 was conducted on 11 583 patients who presented to hospital after DSH between 1978 and 1997. Data were obtained from a general hospital DSH register in Oxford and the Office for National Statistics, and from equivalent mortality registers in Scotland and Northern Ireland.

Results: Three hundred patients had died by suicide or probable suicide. The risk in the first year of follow-up was 0.7% (95% CI 0.6-0.9%), which was 66 (95% CI 52-82) times the annual risk of suicide in the general population. The risk after 5 years was 1.7%, at 10 years 2.4% and at 15 years 3.0%. The risk was far higher in men than in women (hazard ratio 2.8,95% CI 2.2-3.6). In both genders it increased markedly with age at initial presentation.

Conclusions: Following DSH there is a significant and persistent risk of suicide, which varies markedly between genders and age groups. Reduction in the risk of suicide following DSH must be a key element in national suicide prevention strategies.