Numerous studies and reports have shown that ice hockey at the minor league level is often too violent and that modifications are required in how players behave during games (penalties taken) and in their use of body checking. The purpose of this study was to evaluate the effects of an intervention strategy on three dependent variables: the frequency of legal body checks per game, the type and frequency of penalties, and the number of injuries. The intervention strategy, based on self-supervision, was provided to 28 coaches at the Bantam level (14–15 years old). Although the coaches expressed a high level of satisfaction with the content of the intervention strategy, and stated that they would use it in the future, no significant differences were noticed in any of the dependent variables. This study, however, does provide a template for researchers who wish to validate an intervention strategy for coaches working in a normal coaching environment.