Widespread replications of evidence-based prevention programs (EBPPs) prompt prevention scientists to examine program implementation adherence in real world settings. Based on Chen's model (1990), we identified five key factors of the implementation system and assessed which characteristics related to program adherence. The sample included 32 EBPPs and results indicate that target recipient responsivity, program material quality, implementer prioritization, community collaborative system support, and parental support significantly relate to program adherence. Several differences reached statistical significance, thereby highlighting the importance of these variables and the need for future studies with larger sample sizes to identify factors related to program adherence adequately. (Contains 2 tables, 1 figure, and 3 footnotes.)