Substance abuse subtype differences in DSM-IV personality disorders and normal personality dimensions were evaluated in 370 inpatient and outpatient alcohol, cocaine, and opiate abusers. The Type A/Type B distinction was replicated, with Type B substance abusers exhibiting more premorbid risk factors, more severe substance abuse, and greater psychosocial impairment. As predicted, compared to Type A, Type B were more commonly diagnosed with, and had more severe symptoms of, all personality disorders except Schizoid. With regard to normal personality dimensions, Type B scored higher on neuroticism, novelty seeking, and harm avoidance; Type A scored higher on agreeableness, conscientiousness, cooperativeness, and self-directedness. These subtype differences remained after controlling for the effects of antisocial personality and psychiatric symptoms.