This paper reviews the literature on the effect of severe mental illness on other members of the patient's family. The burdens of caring for a patient at home are considerable. They often affect the caring relative's social and leisure activities, and financial problems arise frequently. Relatives have difficulties in understanding and coming to terms with illness-related behaviour. ‘Negative’ symptoms are often a particular problem. Despite their burden, relatives do not complain much, although they receive little support, advice or information from the professionals engaged in treating the patient; much is now known about the difficulties relatives face, but we still need to know how they can best be helped. Failure to do this will have bad effects on both relatives and patients.