There is evidence that patients presenting at a hospital Accident and Emergency (A&E) department with self-harm are considerably more likely than many others to discharge themselves before their assessment or treatment are complete. This paper reports a study that is part of a broader analysis of all self-harm presentations to a hospital A&E department over a five-year period. Self-harm patients who chose to remain for assessment and treatment were compared with those who chose to discharge themselves prematurely. We found a mean proportion of 18% of self-harm patients per annum took early discharge between 1996 and 2000 and noted that these patients were more likely than other self-harm patients to have consumed alcohol in the hours immediately prior to their self-harm and attendance at the hospital. Self-harm patients who took early discharge were less likely than other self-harm patients to be admitted to an in-patient bed and less likely to receive a psychosocial assessment from a mental health specialist. We also found that aftercare arrangements were significantly less likely to be made for those patients who took early discharge. Some suggestions are made about approaches that clinical staff could adopt in order to reduce early discharge in self-harm patients.