Beginning in 1985, The Johns Hopkins University School of Medicine developed a model curriculum on alcohol abuse to enhance the education of medical students in issues related to the abuse of alcohol and other drugs. By 1987, preclinical courses (given in years one and two) reflected the goals of the curriculum; however, integration of the curriculum into the clinical courses (given in years three and four) was only partially successful. This paper reports on nine annual surveys of students (the classes of 1989-1992) that were conducted from 1987 to 1990 to measure the effects of the curriculum, using previously validated instruments to record the students' knowledge, attitudes, beliefs in role responsibility, and confidence in clinical skills. Significant improvements occurred in the students' attitudes, beliefs in role responsibility, and confidence in skills during their preclinical years. These positive changes were stronger, and better sustained during the clinical years, in students who participated in special programs or elective courses focusing on substance abuse; the positive changes were not always sustained in other students. The authors suggest that enhanced experiential sessions, elective programs, and greater emphasis during the clinical years on issues relating to substance abuse are necessary for maintaining the desirable educational outcomes of a substance abuse management curriculum, and that an intensive program against a backdrop of curriculum reform is a useful model.