INTRODUCTION Deliberate self-harm is a common problem that often requires orthopaedic treatment. Patients with injuries due to deliberate self-harm are often referred to our unit, This study assessed the type of treatment required and the cost of treatment. PATIENTS AND METHODS We undertook a retrospective survey of deliberate self-harm patients with known ICD-10 psychiatric disorders admitted for orthopaedic care from a medium-secure, female-only, psychiatric unit, Data were collected on admission rate, duration-of stay, surgical interventions and complications. RESULTS Over 4 36-month period there were 73 admissions for 15 patients (mean age, 25.1 years) requiring 65 operative interventions, a mean of 4.3 (range, 0-9) per patient. Over 50% of patients were admitted more than 3 times, totalling 416 hospital bad-days and 80% had methicillin-resistant Staphylococcus aureus (MRSA) isolated. The orthopaedic treatment costs for these patients was 453,000 pound during the period studied. DISCUSSION The significant resources required to manage this patient cohort demonstrates the need for a co-ordinated management policy. We recommend day-case surgery for infected wounds only. Postoperatively, wounds should be protected with plaster of Paris, Ail patients with deliberate self-harm should be regarded as being infected with MRSA.