This article assessed the impact of knowledge of breast cancer and type and intensity of participation in a church-based breast cancer education program and other factors on mammography screening among African Americans and Latinas. Logistic regression was used to assess the impact of these factors on self-reported mammography utilization. Passive participation in church-sponsored activities, measured by breast cancer information that was heard, seen, or read, was found to be significantly associated with the likelihood of mammography use among African Americans. Moreover, African Americans who reported hearing, seeing, or reading about mammograms at their churches four or more times were 15 times more likely to report mammography use within the past year than were those who encountered information only once. Messages from pastors and church bulletin announcements were the most significant predictors. An increase in knowledge was not associated with higher mammography use. For Latinas, none of the hypothesized knowledge or participation variables was found to be significant. The results suggest that faith-based breast cancer programs can be effective by adopting tailored strategies to raise awareness about the importance of early detection.