A search was made of records available for 65 nonpsychotic patients referred to a psychiatric day hospital. Assessments were made of whether they had shown various specified types of deviant social conduct, such detailed objective surveys of social conduct being regarded as superior to the use of concepts such as "psychopathic personality". The correlational structures of the areas of deviance produced four factors, i.e. deviant family roles, poor social integration, violence, and a more heterogeneous antisocial behaviour factor. The relationship was examined between areas of deviance and indices of the course and outcome of day hospital admission. The prognostic significance of social deviance was different for men and women; for example, only men showed a correlation between the number of areas of social deviance and the outcome of day hospital admissions. Violence and poor social integration showed no relation to outcome at all. It is suggested that there is no basis for excluding such patients from day hospitals on the assumption that they are less likely to be helped than other non-psychotic patients.