An investigation was conducted over a 40-week period in which staff completed weekly a list of 34 items representing aspects of disturbance for all patients in a modified therapeutic community comprising male and female wards. Four principal components accounted for about half the variance in both the men's and women's disturbance data. The first components in both groups represented general disturbance. Subsequent components in the men concerned rejection and withdrawal, nocturnal disturbance, and physical aggression, whilst among the women the later components reflected hysterical acting-out, withdrawal and 'opting out', and self-directed and indirect forms of aggression. There was only an insignificant relationship between the general disturbance levels in the two wards. A number of variables, including the level of disturbance predicted from the diagnostic composition of the ward, average length of stay, and numbers of patients in the wards were found to correlate with the weekly levels of disturbance. In the men's ward, a 12-week cycle of general disturbance was found. An occasion of disruption to the routine of the unit (Christmas) was implicated in an episode of high disturbance.