Type 2 diabetes is epidemic in the United States with greater incidence rates in African-American communities. Lifestyle interventions during the phase of insulin resistance mitigate cardiovascular risk and prevent diabetes. The primary aim of this study is to test the impact of a Community Health Advisor (CHA)-based diabetes prevention controlled intervention in urban African-American communities. In this controlled trial, church congregants in New Haven, CT, receiving a 1-year CHA-led diabetes prevention intervention were compared with church congregants in Bridgeport, CT, who did not receive an intervention. Outcome measures included physical activity, dietary pattern, anthropometric measure, social support, diabetes knowledge, nutrition and exercise self-efficacy. The results indicate that at the end of the 1-year intervention period, there were no significant differences observed between intervention and control groups. Possible explanations for the lack of change include difficulty in engaging the CHAs, variability in the CHA-led interventions, baseline discrepancies between the two sites which could not be fully controlled and loss to follow-up. The results indicate important obstacles which impeded the successful implementation of this intervention and lessons learned for future interventions.