The direct costs to the mental health services for patients who participated in a trial of a behavioural family intervention to reduce schizophrenic relapse were estimated. Comparisons were made between two patient groups from households of high expressed emotion (HEE): one group received a nine-month family intervention (HEE Intervention) and the other group routine treatment (HEE Control). A third group consisted of patients from low-EE households (LEE Control). The significant decrease in relapse rates in the HEE Intervention group compared with the HEE Control group has previously been reported; the analysis of costs indicates that any increase in costs due to the family intervention is outweighed by a decrease in usage of the established mental health services. The intervention resulted in a decrease of 27% in mean cost per patient.