There is a need to improve girls’ physical activity (PA) in afterschool programs as girls’ PA levels are consistently lower than boys’. An evidence-based professional development framework, the 5 Ms, has been effective in helping staff to improve PA in both girls and boys but further improvements in girls’ PA are needed. Little is known about staff’s perceptions of using PA promotion strategies to promote girls’ PA. Therefore, the purpose of this study was to explore staff perceptions of the use of evidence-based PA promotion strategies for promoting PA in girls. Semi-structured interviews were conducted with staff from three community-based afterschool programs located within a school setting (n = 18). Data were analyzed using the process of immersion/crystallization. A majority of staff had some knowledge of PA promotion strategies but few staff consistently utilized these strategies and a majority felt several strategies were unnecessary (i.e., having a PA policy). Newer staff reported depending on senior staff to promote PA in girls. Overall, findings suggest that staff’s perceptions may impact their use of PA promotions strategies. The results of this study will contribute to the enhancement of an existing staff training framework (the 5 Ms) to improve girls’ PA in afterschool programs.