Children across Canada participate in a variety of organized sports (Active Healthy Kids Canada, 2015) and parents are a vital part of children's sport experience as both practical (e.g., driving to practice, signing up, etc.) and emotional supporters (Omli & Wiese-Bjornstal, 2011). Many parents' support is positive, with parents displaying good behavior while watching youth sport events, however poor behavior still exists on youth sport sidelines and can take away from the overall enjoyment for young athletes (Bowker et al., 2009). Using research from sport psychology and sport management, this study examined, from the perspective of parents, whether personal (gender and previous sport experience) and situational (sport type, stakes, and occurrence) factors influenced behavior on baseball and ice hockey sidelines during youth sport events. Bronfenbrenner's (1977) ecological model was used to organize previous research and, combined with the general aggression model (Anderson & Bushman, 2002), created the multi-disciplinary framework used to guide the study presented here. 1040 parents from provincial sport organizations in western Canada completed a survey providing insight into their perceptions of behavior on youth sport sidelines. While some differences were found in the personal and situation factors examined, overall poor behavior was not reported frequently and was generally considered unacceptable. There were some areas identified where parent behavior can improve however, and these results can be used by sport organizations to educate parents and inform policy around behavior on youth sport sidelines, as well as guide future sport parent research.