This study is designed to examine the prevalence, demographics, and the Axis I and Axis II diagnoses of sadistic personality disorder (SPD) in a previously unexamined population (outpatient veterans). It also represents the first attempt to examine the family history of those with SPD. Standardized methods were used to select 144 nonpsychotic subjects from a veterans psychiatric outpatient clinic. The population was then divided into three groups: those with SPD, those without SPD but with antisocial personality disorder or traits, and those with no Axis II disorders. A fourth group consisted of 28 control veterans without psychopathology. Subjects with SPD tended to be younger and to have lower scores on the Global Assessment Scale than did clinical control subjects without personality disorders; they also had significantly more bipolar and panic disorder than were found in the antisocial traits group. High levels of depression and alcohol dependence were also present. SPD traits correlated with DSM-III-R dramatic cluster, compulsive, passive-aggressive, and self-defeating personality disorders. The SPD group could be distinguished from other groups on the basis of family history. It was concluded that sadistic personality traits and disorders are prevalent (8.1%), associated with reduced functioning, and may have specific associations with certain Axis I and Axis II disorders. It is possible that they have a distinct familial pattern.