Alcohol and other substance use disorders are highly comorbid, but little is known about patterns of polydrug use in adolescents with different levels of alcohol involvement. This research examined patterns and correlates of polydrug use in 176 adolescent drinkers with DSM-IV alcohol dependence (n = 61), alcohol abuse (n = 57), and no alcohol diagnosis (n = 58). Alcohol and other Substance Use Disorders were assessed using a modified version of the Structured Clinical Interview for the DSM. Lifetime histories of alcohol use and other drug use were assessed using a structured interview. Subjects also completed a questionnaire measure of the frequency of use of specific alcohol-drug combinations. The total number of illicit drugs ever used was greater in the alcohol dependence (mean = 3.8, SD = 2.1) and abuse groups (mean = 3.0, SD = 2.1), compared with the no-alcohol diagnosis group (mean = 1.9, SD = 1.3). Consistent with previous findings, there was a consistent pattern in the age of onset of psychoactive substance use: alcohol, followed by marijuana, followed by other drugs. The recent use of alcohol and other drugs in combination was reported by a greater percentage of subjects in the alcohol dependence (69%) and abuse groups (72%), compared with drinkers without an alcohol diagnosis (45%). The most common alcohol-drug combination was alcohol with marijuana (58% of the total sample), followed by alcohol-hallucinogens (16%). The frequency and extent of polydrug use was associated with being older and having higher levels of behavioral undercontrol and negative emotionality. Adolescent polydrug use, particularly the use of alcohol and other drugs in combination, is an important area for research, treatment, and prevention.