Background The relative burden and risk of readmission for people with personality disorders in hospital settings is unknown. Aims To compare hospital use of people with personality disorder with that of people with other mental health diagnoses, such as psychoses and affective disorders. Method Naturalistic study of hospital presentations for mental health in a large community catchment. Mixed-effects Cox regression and survival curves were generated to examine risk of readmission for each group. Results Of 2894 people presenting to hospital, patients with personality disorder represented 20.5% of emergency and 26.6% of in-patients. Patients with personality disorder or psychoses were 2.3 times (95% CI 1.79-2.99) more likely than others to re-present within 28 days. Personality disorder diagnosis increases rate of readmission by a factor of 8.7 (s.e. = 0.31), marginally lower than psychotic disorders (10.02, s.e. = 0.31). Conclusions Personality disorders place significant demands on in-patient and emergency departments, similar to that of psychoses in terms of presentation and risk of readmission.