Research on adult alcohol and tranquilizer use provides strong evidence of fundamental sex differences in the use of the two types of drugs. Current explanations posited for these differences center around differential sex roles and sex role expectations. Much of the discussion of these differences suggests that as male and female roles converge, these behavioral differences should decrease. Using data from a statewide survey of Illinois adults, we provide a preliminary test of a sex role convergence hypothesis for alcohol and tranquilizer use. To do so, we use a multinomial extension of logistic multiple regression. After controlling for demographic and sex role characteristics, the results show that females have a much higher probability of using tranquilizers rather than alcohol than men do. Thus, the role convergence hypothesis is not supported for the use of these two types of drugs.