The aim of the project was to investigate differences between outpatients with Severe Mental Disorders (SMDs) with and without a history of Self-Harm behaviour (SHb) and/or Violent behaviour against other people (Vb) in relation to: (a) socio-demographic and clinical characteristics, (b) violent behaviour during a 1-year FU, (c) predictors of SHb and Vb during the FU. Outpatients with SMDs, with and without a history of Vb were enrolled. They were divided in four groups: patients with lifetime Vb (V), patients with both Vb and SHb (V-SH), patients with only SHb (SH) and patients with no history of SHb and Vb (control group, CONT). The frequency and severity of SHb and Vb during the FU were assessed every two weeks by the MOAS. Overall 246 patients were enrolled. BPRS-E Depression item, the SLOF Social acceptability, the BDHI Indirect Aggression, the BIS Motor Impulsiveness and the STAXI-2 Control-Out showed significant correlations with all the four groups (p < 0.030). V and V-SH patient groups reached higher scores in all MOAS sub-scales. Age among the SH group and BPRS-E affect-anxiety subscale among the V group significantly predicted aggression against people. In people with SMDs a history of SHb or Vb is associated with different medium-term outcomes.