Improved agricultural inputs-including seeds, fertilizer, and pest control products-are necessary for raising farm productivity in Africa. Yet, in many locations, variable input quality and a proliferation of unregistered brands make product selection and calibration of optimal dosages difficult for farmers. Unregistered pesticides pose two specific quality problems: frequent underdosage and, in some cases, inclusion of banned substances. In response to widespread farmer complaints, this study estimates the prevalence of unregistered pesticide products by conducting a detailed survey of agricultural input retailers in 10 major agricultural markets across Mali. The article explores resulting risks and responses by private and public sector stakeholders through structured interviews with key informants in those same markets. The findings suggest widespread sales of low-cost, unregistered pesticides. In the 10 markets surveyed, unregistered products accounted for 26% of total pesticide volumes sold, posing risks to farmers, traders, and the environment. In response, farmer support groups and pesticide trade associations have begun to fight back through education and awareness campaigns, agro-input dealer training, farmer outreach, and in some cases, joint bulk procurement. To reinforce these initiatives, the survey results suggest two low-cost indicators for spatially targeting regulatory enforcement efforts.