The Gang Resistance Education and Training (G.R.E.A.T.) program differs from typical efforts to reduce gang involvement in that the G.R.E.A.T. program does not target at-risk youth but rather targets its classroom-based program at all middle school students. The three main objectives of the 9-hour curriculum taught by uniformed officers are to: (1) reduce involvement with gangs and delinquent behavior; (2) teach the consequences of gang involvement; and (3) help students develop positive attitudes toward law enforcement. Two studies were employed to evaluate the effectiveness of the G.R.E.A.T. program: a 1-year cross-sectional study and a 5-year longitudinal, quasi-experimental study. An evaluation survey was presented to participants when they were in 7th grade and re-administered annually through 11th grade. Results of the evaluation indicated modest positive results. G.R.E.A.T. demonstrated effectiveness at changing several risk factors for delinquency and gang involvement, indicating that future negative behaviors are preventable through risk-focused prevention approaches. Moreover, G.R.E.A.T. met two of its program goals: (1) it effectively helped students develope positive attitudes towards law enforcement; and (2) raised their awareness of the negative consequences of gang involvement. The third program goal of reducing gang membership and delinquent behavior was not achieved. Parent and educator surveys indicated positive attitudes toward G.R.E.A.T. and most parents agreed that unformed police officers should be in the classroom and would make good instructors. Since the G.R.E.A.T. program alone will not keep children from joining gangs, additional strategies should be developed to meet that key goal.