Objectives: The purpose of this study is to examine the extent to which participation in a county-wide prevention program leads to improvements in protective factors associated with child abuse prevention (CAP) and whether improvements in measured protective factors relate to decreased odds of child abuse. Method: Using multilevel growth modeling, our analyses focus on an economically poor, culturally diverse sample of 1,184 mothers who maintained their involvement in the program for at least 6 months. Results: Our results support a limited association between program participation and improvements in maternal protective factors. Nevertheless, pursuant to the working theory of many CAP programs, improvements in maternal social support and mental health, when evident, were significantly associated with reduced odds of child abuse. Conclusion: More robustly specified interventions and supports are needed to enhance outcomes for the majority of families targeted by the program, including those who present the greatest vulnerability for child abuse. (Contains 7 tables.)