Isolating risk factors associated with drug and alcohol use and abuse has been a major task for many researchers. A study was designed to determine whether longitudinal models of social conformity and drug and alcohol use would provide similar results for males and females. Data were obtained from 654 young adults (192 males, 492 females) who had participated in a longitudinal study of adolescent development and drug use. The impact of social conformity on alcohol and hard drug use was tested in a series of latent variable longitudinal models separately for men and women and then contrasted directly. Social conformity measured at high school age (year 5 of the study) was used as a predictor of less alcohol and hard drug use at young adulthood (year 9). The results showed that social conformity predicted less hard drug use for both males and females and less alcohol use for females only. Structural patterns between latent variables were quite similar for both males and females for hard drug use, but less so for alcohol use. These findings suggest social implications of the differential acceptability of alcohol use by sex. (Author/NB)