This study compared 248 graduating seniors with 301 beginning juniors at 10 bachelor's-level social work programs in the Northeast concerning their knowledge and attitudes regarding working with substance-abusing clients. Graduating seniors demonstrated modestly higher levels of knowledge and only slightly more positive attitudes toward working with this population. In a multivariate analysis, however, having taken a substance abuse course in college or training in settings outside of school improved students' attitudes in this regard. The students' ethnic/racial identity and personal exposure to substance abuse through family, close friends, or self also had a significant impact on their knowledge and attitudes. (Contains 4 tables.)