Histories of serious suicide attempts & slashing were investigated in a sample of 304 Finnish fire setters. Major mood disorders, father’s alcoholism, & suicidal motive of fire setting were significantly associated with suicide attempts. Among fire setters, non-lethal slashing was a predictor of serious suicidality. Associations between psychiatric diagnoses, family history, & suicidality among fire setters are similar to those reported for suicidal patients with mood & substance abuse diagnoses. Studying fire setters who exhibit an extremely high incidence of suicidal behaviour is an effective way to elucidate the psychobiology of suicidal behaviours. (40 refs.) JA