The cognitive difficulties associated with the disorder of schizophrenia seem to be predictive of future dependence on psychiatric services and predict social functioning. Cognitive remediation therapy (CRT) was designed to rehabilitate these cognitive functions, and the interest in it has grown dramatically over the past ten years. However, the programmes are rarely based on clear theoretical principles and sometimes rely heavily on practice rather than guided learning. The evidence for their efficacy is variable and seems to be dependent on the use of specific components of training. The current review tries to put this evidence into context and sets out a programme of research, which is essential in this area if future progress is to be made.