This study considered the use of staff observation and patient's self-ratings of subjective psychopathology on admission to a psychiatric intensive care unit. The aim was to evaluate these measures as a means of predicting subsequent assaults and self-injury during the patients' stay on the ward. Few studies have shown a relationship between subjective experience and observable violent behaviour although some have found a correlation with ‘violence potential’. Eichelman & Hartwig (1990) have suggested the use of the SCL-90 hostility subscale, although doubts have been expressed about the ability of psychotic patients to complete such questionnaires reliably. The usefulness of both patients' self-ratings and staff observation would lie in their ability to help staff predict violence and self-injury and to take appropriate action.