This study reports the results of the process evaluation component of the Process and Outcome Evaluation of the Gang Resistance Education and Training (G.R.E.A.T.) program. The process evaluation consisted of multiple methods to assess program fidelity: (a) observations of G.R.E.A.T. Officer Trainings (G.O.T); (b) surveys and interviews of G.R.E.A.T.-trained officers and supervisors; (c) surveys of school personnel; and (d) ‘‘on-site,’’ direct observations of officers delivering the G.R.E.A.T. program in the study sites. Results illustrate a high level of program fidelity, providing greater confidence in any subsequent outcome results.