Objectives (1) investigate risk factors associated with repeated deliberate self-harm (DSH) among patients attending the emergency department due to DSH, (2) stratify these patients into risk categories for repeated DSH and (3) estimate the proportion of repeated DSH within 12 months.

Design A consecutive series of individuals who attended one of Scandinavia's largest emergency departments during 2003–2005 due to DSH. Data on sociodemographic factors, diagnoses and treatment, previous DSH at any healthcare facility in Sweden (2002–2005) and circumstances of the index DSH episode were collected from hospital charts and national databases. A nationwide register based on follow-ups of any new DSH or death by suicide during 2003–2006.

Main outcome measure Repeated DSH episode or suicide.

Results 1524 patients were included. The cumulative incidence for patients repeating DSH within 12 months after the index episode was 26.8% (95% CI: 24.6 to 29.0). Risk factors associated with repeating DSH included previous DSH, female gender, self-injury as a method for DSH and if the self-injury required a surgical procedure, current psychiatric or antidepressant treatment and if the patient suffered from a substance use disorder or adult personality disorder or did not have children under the age of six.

Conclusion Patients attending an emergency department due to DSH have a high risk of repeating their self-harm behaviour. We present a model for risk stratification for repeated DSH describing low-risk (18%), median-risk (28% to 32%) and high-risk (47% to 72%). Our results might help caretakers to direct optimal resources to these groups.