The study used system dynamics modeling computer simulations to gain a better understanding of the process of delivering small-group, evidence-based HIV prevention programs in the community and to explore implications for public health practice. A model was developed to explain provider-reported challenges associated with recruiting, retaining, and graduating people from small-group workshop programs. The model simulations revealed the difficulty in sustaining high rates of recruitment and retention in small-group programs over time. The model simulations provided insight into what processes may lead to suboptimal numbers of people being recruited and positively influenced by these programs.