Men who have sex with men (MSM) represent the largest group with HIV in the U.S. (CDC 2005). Interventions for prevention with HIV-infected MSM are urgently needed, and integrating prevention into HIV care represents one opportunity for this advancement. This article describes the development and results of initial pilot testing of a behavioral intervention to reduce HIV sexual risk transmission behavior for HIV-infected MSM that is integrated into HIV care. To illustrate our intervention development process, we describe the setting and population (HIV-infected MSM patients at Fenway Community Health in Boston) for the project, the initial conceptualization of the project including its guiding conceptual model (information, motivation, and behavioral skills model, IMB: Fisher and Fischer 1993), the iterative process of attaining and integrating input from stakeholders, the use of peer interventionists, the open phase pilot and participant input, an overview of the intervention content, and, finally, lessons learned. The result of this process is an example of an intervention developed with strong input from the community and other stakeholders, which is ready for further testing in a randomized controlled trial.