Excess weight is a common problem in the general population and in those with severe mental illness and is associated with a range of adverse consequences. The evidence base for managing excess weight in those with severe psychiatric illness is small. We report the outcome of a weight management programme provided in a community mental health centre. The programme consisted of group sessions, held weekly and lasting one hour. Participants self-referred and attended as many sessions as they wished. Sessions included weighing, feedback from participants and education on a range of issues including healthy eating and exercise. Over a 3-year period 70 patients, predominantly with schizophrenia, attended the programme. Length of follow-up ranged from 2 weeks to 3 years. Data for all 70 patients was evaluated. The mean BMI at entry to the programme was 32.5 kg/m2. The mean number of sessions attended was 34. Patients achieved a mean weight loss of 4.97 kg. The mean BMI at last attendance was 30.7 kg/m2. Weight loss correlated with number of sessions attended (p = 0.0001). This study demonstrates the long-term value of a weight management programme at 3 years and supports the hypothesis that weight loss can be achieved using a simple behavioural intervention in motivated psychiatric patients.