This study describes the prevalence, clinical characteristics, and gender profile of self-harm in a cross-sectional sample of 388 patients with schizophrenia spectrum disorders. All patients were interviewed and assessed with respect to lifetime self-harm and relevant clinical variables. An overall of 49% of the patients reported self-harm which was associated with female gender, having had a depressive episode, younger age at psychosis onset, alcohol abuse or dependence, current suicidality, awareness of illness, and low adherence to prescribed medication. Higher awareness of having a mental disorder was associated with self-harm in men only, while emotional dysregulation was associated with self-harm in women only. We conclude that while self-harm in patients with schizophrenia spectrum disorders is highly prevalent in both genders, risk factors in men and women differ in several important ways.