The aim of the present study was to clarify the relationships between testosterone and alcohol abuse, alcohol dependence and specific personality characteristics and behaviors in a forensic psychiatric population. Serum levels of total testosterone (TT), free testosterone (FT-DPC) and sex hormone-binding globulin (SHBG) were determined in 61 male subjects undergoing forensic psychiatric examinations. All subjects had been detoxified from drugs and alcohol during previous incarceration in jail or hospital. TT and FT-DPC were found to be highly correlated (r=0.63, P < 0.0001). High concentrations of TT and SHBG were consistently related to type II alcoholism, but not pure alcohol dependence. TT and SHBG were also related to antisocial personality disorder. Furthermore, TT and SHBG were related to socially deviant behavior, reflected in factor 2 in the Psychopathy Checklist (PCL-R). In a multiple regression, FT-DPC was also clearly associated with the psychopathy-related scales of the Karolinska Scales of Personality (KSP) when age and signs of hepatic damage were kept under control.