The effectiveness of a rehabilitation intervention (Boston University Model) was investigated in a one-year prospective naturalistic study among 35 clients with mainly psychotic or affective disorders and dependent on mental health care with at least one hospital admission in the past five years. Rehabilitation was successful in goal-attainment after 1 year (46% fully, 34% partly). Although rehabilitation did not make clients less dependent upon care, it decreased the number of needs and had a positive effect on the match between care needed and care provided. No evidence was found for a significant effect of rehabilitation clients' quality of life and functioning, although social functioning became more in line with the seriousness of psychiatric impairment.