Substance abuse prevention counseling can be found in two venues: school counseling and student assistance programs (SAPs). School prevention counseling is based on school psychology and guidance counseling. The authors of this article did not find any empirical studies of prevention counseling. Six criteria were used to assess the published research on SAPs: research designs, sampling methods, measures, procedures, analyses, and peer review of results. SAP studies reviewed were placed in one of three levels: Rigorous (N = 3; met all inclusion criteria), Informative (N = 2; met all criteria except peer review), and Evaluative (N = 5; weak design, but explicit in describing methods). The Rigorous Studies found a decrease in substance use or risk factors. The two Informative Studies found a decrease in substance use. The Evaluative Studies demonstrated the prevention of increases in substance use. (Contains 3 tables.)