The purpose of this article is to identify characteristics of Black barbershop clients and barbers in an urban Midwestern city participating in a health promotion program called Affecting Cancer Together (ACT) that are associated with client knowledge about prostate cancer. Statistical analyses examined client and barber characteristics for their potential association with client prostate cancer knowledge, while controlling for ACT variables. Study findings suggested clients who are married (ß = 0.99; confidence interval [CI] = 0.38, 1.59; p < 0.01) and have higher levels of education (ß = 0.34; CI = 0.01, 0.67; p = 0.04) may be more likely to know more about prostate cancer. Barbers with at least "some college" education may be more effective in increasing client knowledge (ß = 0.85; CI = 0.05, 1.64; p = 0.04). Trained peer-helper programs may consider prioritizing limited educational resources for barbers with at least some college education and incorporating the social support of spouses for making informed decisions. Considering the potential of barbershop programs to reach Black men about a serious racially disproportionate health issue, ameliorating adoption, implementation, effectiveness, and sustainment are an important public health priority for underserved populations.