With the increasing emphasis on evaluating the effectiveness of community-based organizations' HIV prevention programs, the needs, concerns, and strategies related to having stakeholders participate in designing and conducting an outcome evaluation need to be discussed. Stakeholders' participation in outcome evaluation ensures its relevancy and fairness. Participatory outcome evaluation starts with assessing the feasibility of conducting an outcome evaluation and determining whether stakeholders have a need for an outcome evaluation. If an outcome evaluation is possible and needed, the areas in which stakeholders can make important contributions to the evaluation are negotiated with the stakeholders. The article also discusses strategies to improve stakeholders' use of the results of outcome evaluation.