A total of 1,734 persons were prospectively screened in a primary care clinic to examine the demographic characteristics and presence or absence of antisocial personality disorder among early onset alcoholics (EOA) and late onset alcoholics (LOA). A total of 76 EOA (male = 58 and female = 18) and 80 LOA (male = 56 and female = 24), as determined by the Comprehensive Drinking Profile Scale, participated in the study. EOA tended to be single and were younger, in a lower socioeconomic class, raised by non-biological parents, more likely to have antisocial personality disorder, and more likely to commit certain convicted offenses compared to LOA (p <or= .05). This study found that EOA identified in a primary care clinic have a different demographic profile and are more likely to have antisocial personality disorder compared to LOA.