The effectiveness of collaborative environmental decision-making processes hinges on the degree to which participating stakeholder groups (i.e., policy actors) perceive those processes to be fair. However, there is limited understanding of the factors that shape actors' perceptions of the fairness of decision-making processes, a concept known as perceived procedural fairness. I develop and test a set of hypotheses about the conditions under which actors that participate in the same environmental decision-making processes perceive the fairness of those processes differently. The study draws upon data from a survey of policy actors participating in task forces, steering committees, and other forums that guide climate change adaptation decision-making in the Lake Victoria basin in East Africa. These actors vary significantly in power and capacity, which raises questions of the degree to which forums provide meaningful opportunities for all actors to contribute to decision making. Findings indicate that among pairs of actors participating in any given forum, satisfaction with procedural fairness is higher among actors with greater social capital, operating at higher administrative levels, and with larger numbers of staff members. Additionally, donor organizations perceived higher levels of procedural fairness compared to civil society, government, and international nongovernmental organizations. These results have implications for efforts to improve the efficacy and legitimacy of environmental policy making in the Lake Victoria basin, as well as other transboundary governance systems in developing regions.