This article presents results from a randomized control trial of the Gang Resistance Education and Training (G.R.E.A.T.) program; 3,820 students enrolled in 195 classrooms in 31 schools in seven cities were surveyed six times over 5 years (pretests and posttests in Year 1 and four annual follow‐up surveys). The results indicate that during the 4 years posttreatment, students who received the program had lower odds of gang membership compared with the control group. The treatment group also reported more prosocial attitudes on several program‐specific outcomes. In addition to examining the effectiveness for the full sample, we also report analyses that examine program effects by (a) site and (b) initial levels of risk for gang membership.

Policy Implications

Effective youth violence‐prevention programs continue to be few in number; effective youth gang‐prevention programs are even rarer. Various rating systems exist (e.g., University of Colorado's Blueprint Model, Helping America's Youth, OJJDP Model Program Guide, and NIJ's Crime Solutions), but even application of the least rigorous standards fails to identify many promising or effective programs. Based on results reported in this article, the Gang Resistance Education and Training (G.R.E.A.T.) program holds promise as a universal gang‐prevention program.