Altered autonomic arousal in relation to offending behavior has mainly been investigated in subjects with varying degrees of psychopathic traits. The present study sets out to investigate subjective ratings and skin conductance responses (SCRs) in mentally disordered offenders with various diagnoses but without psychopathy, specifically recruited from the forensic psychiatric system. Two subgroups were investigated; an antisocial group with antisocial personality disorder (APD) or antisocial traits (n=16) and a non-antisocial group with various diagnoses (n=25), in relation to a healthy non-criminal control group (n=20). All participants were male. SCRs and subjective ratings of arousal and valence were measured for neutral and negative pictures from the International Affective Picture System (IAPS). The offenders showed significantly lower SCRs and subjective ratings than the control group. Moreover, there was no significant difference between antisocial and non-antisocial offenders, indicating that antisocial behavior might not be a differential factor. Thus, attenuated emotional responses may be a characteristic shared by mentally disordered offenders overall.