Alcohol use and associated factors were studied in 124 consecutive cocaine-dependent admissions to an outpatient substance abuse clinic. Two analyses were conducted: First, those who did and did not meet criteria for current alcohol dependence were compared on sociodemographic and drug use characteristics. Second, patients who reported simultaneous cocaine and alcohol use on > 50% vs. < or = 50% of the occasions that they used cocaine were compared using the same dependent measures. Fifty-seven percent of patients met criteria for current alcohol dependence. Those with and without alcohol dependence did not differ on any sociodemographic characteristics, but those with dependence scored higher on the alcohol and family subscales of the Addiction Severity Index, the Michigan Alcoholism Screening Test, and measures of alcohol use, and were more likely to use cocaine and alcohol simultaneously, to use cocaine with friends and in social settings, and were more likely to report financial difficulties and unwanted sexual relations as adverse consequences of their cocaine use. Sixty-four percent of patients reported > 50% simultaneous cocaine and alcohol use. The two groups did not differ on any sociodemographic characteristics, but those reporting greater simultaneous use were more likely to be alcoholic, scored higher on most measures of alcohol use, and were more likely to report using cocaine with friends and in social settings. The only other differences observed between the two groups were fewer reports of seizures or difficulty concentrating in the group reporting greater simultaneous use. The present results confirm prior reports on the widespread prevalence of alcohol dependence among cocaine-dependent patients and extend them by providing new information on the prevalence and other characteristics of simultaneous cocaine and alcohol use.