High variability of nonpoint source (NPS) pollutant loads caused primarily by uncontrollable precipitation events creates great uncertainty for those charged with NPS management. Stakeholder disagreement on the best way to address the uncertainty issue can lead to inaction. However, understanding different stakeholder perspectives could promote consensus and a unified effort to effectively address this difficult pollution problem. This paper probes methodologies for quantifying the uncertainty of soil erosion and sediment load predictions and evaluates stakeholder perceptions of the issue through a focus group study. Three groups, each consisting of 5 to 8 individuals, convened to answer a set of questions designed to promote discussion of soil erosion and sediment load prediction uncertainty. One group was composed of natural resource professionals and scientists, another of individuals with environmental interests, and the third of producers and producer association representatives. The goal of the study is to gain insight into perceptions of NPS pollution uncertainty, the need for its quantification, and its impact on water quality improvement efforts. The findings of this study have important implications for EPA’s TMDL program and other NPS pollution control initiatives.