Objective: Self-harm is closely related to completed suicide, especially in older age. As empirical research of self-harm in older age is scarce, with no studies confined to first-ever episodes in older age, we examined the clinical characteristics and the risk of repetition in first-ever self-harm in older age. Method: The Manchester Self-Harm (MaSH) project, a prospective cohort study, gathered data from September 1, 1997, through August 31, 2007, for individuals presenting with self-harm at emergency departments of 3 large hospitals in North West England. The characteristics of older patients (aged ≥ 55 years) who presented with a first-ever episode of self-harm are described and compared to those of middle-aged patients (35-54 years) presenting with a first-ever episode of self-harm. Following each episode, the MaSH form, a standard assessment form developed for the MaSH project, was completed by a clinician. Potential risk factors for repetition were examined by Cox regression analyses. Results: A total of 374 older patients and 1,937 middle-aged patients presented with a first-ever episode of self-harm. The circumstances at the time of self-harm suggested higher suicidal intent in older age. In comparison with middle-aged patients, the rate of repetition in older-aged patients was lower (15.4% versus 11.8%, respectively; hazard ratio for older age = 0.65; 95% CI, 0.45-0.93; P = .019), although repetition was more often fatal among the older group (3.3% versus 13.6%, respectively; P = .009). The most important predictor of repetition in older age, ie, physical health problems, had no predictive value in middle-aged patients, whereas psychiatric characteristics had little impact on the risk of repetition in old age. Conclusions: High suicidal intent and different predictors of repetition in first-ever self-harm in older age highlight the need for age-specific interventions beyond the scope of psychiatric care alone. © Copyright 2011 Physicians Postgraduate Press, Inc.