The present study analyzes course and predictors of physically aggressive behaviour over a 1-year follow up in a sample of patients discharged from a psychiatric inpatient unit. One hundred and eighty-six patients discharged from a locked short-term Psychiatric Inpatient Unit at the Bologna University Hospital. After discharge, two data collection contacts at 1 month and at 1 year were scheduled. In particular, psychiatrists, nurses, and other professionals were interviewed by the research staff using the Overt Aggression Scale. About 20 % of discharged patients showed physical aggressiveness in subsequent follow-up contacts. Risk factors for physical violence in the short-time period were social problems and a longer time from the first psychiatric contact. Living in residential facilities and physical aggressiveness during hospitalization were correlated to violence in the long-time period. Risk factors for physically violent behaviour differed in the short-term and long-term follow-ups; different causes of violent behaviour could be hypothesized.