A group of former abusers, half of whom had been incarcerated, participated in a university substance abuse education course. Knowledge, attitudes and drug usage were measured prior and subsequent to the course. Similar data were gathered on regular college students. The former abusers/offenders increased their knowledge significantly, became significantly less accepting in some attitudes, and showed nonsignificant reductions in drug use. No detrimental effects accrued to college students in the same classroom with the former abusers/offenders. (Author abstract)