Expectations of the effects of alcohol have been related to drinking behaviors for both problem and nonproblem drinkers. The present investigation expanded on previous research by considering age, sex, and alcohol expectancies as differential predictors of frequency and quantity of drinking. Subjects, 157 males and 168 females, completed alcohol expectancy, drinking habits, and demographic questionnaires. Results showed significant sex differences in predictors of drinking frequency. Males who reported most frequent drinking tended to have stronger expectations of increased Social and Physical Pleasure, Global Positive Changes, and Sexual Enhancement. On the other hand, frequent consumption among females was best predicted by stronger expectations that alcohol would reduce tension. The amount consumed per drinking occasion was predicted by the same two expectancy factors for males and females: Social and Physical Pleasure and Social Assertion. Age was an important contributing predictor of quantity and frequency for females only. Results indicated the importance of investigating the mediating role of expectancies (a) within sex and (b) with respect to frequency versus quantity of drinking behavior.