The current research was designed to assess the effectiveness of one nationally prominent and highly publicized driving while intoxicated (DWT) prevention program for youth, Students Against Driving Drunk (S.A.D.D.). Process and outcome data were collected over a 2-year period in two states-California and New Mexico. In each state, one treatment school which implemented S.A.D.D. was compared to a closely matched comparison school on a variety of DWI-related measures over three waves of survey data collection. Process data indicated that in neither school was the entire S.A.D.D. model implemented. Student participation was moderate in the California school and marginal in the New Mexico school. There was also little evidence that S.A.D.D. stimulated increased curriculum attention to DW1 issues.Outcome data provided no evidence for effects of S.A.D.D. on any of the DWI measures. General maturational trends in these variables were observed in the study cohorts, but these trends were not differentiated between the treatment and comparison schools. There was also no support for the concern that S.A.D.D. may stimulate student drinking by encouraging alternative means of transportation for intoxicated students.