The study examined the effect of Stakeholder involvement on public policy implementation in Local Governments of Uganda. The objectives were: to examine how involvement in problem identification, policy adoption, and policy analysis affects implementation of Prohibition of Counterfeit agricultural inputs in Ntoroko district. The study employed case study design and used qualitative and quantitative paradigms. The sample size was 266 people of Ntoroko District Local Government and other stakeholders and the sampling techniques employed were purposive and simple random sampling. Consequently, the data collection methods were survey, interview and document review. Data was collected using self-administered questionnaires and interview guides as well as reviewing scholarly documents. Quantitative data was analysed using descriptive and inferential statistics to test the magnitude of effect of the independent variable on the dependent variable. Qualitative analysis was done through thematic analysis and generation of themes in a narrative procedure. It was established that involving stakeholders in problem identification, policy adoption and policy analysis has had a positive and significant effect on the implementation of prohibition of counterfeit agricultural inputs in NDL. It was concluded that improvements in stakeholder involvement (problem identification, policy adoption and policy analysis) would lead to improvement in policy implementation of counterfeit agricultural inputs policy in Ntoroko district. The study recommends the following: All stakeholders should be sensitized about the counterfeit agricultural inputs policy and their views should be considered during the counterfeit agricultural inputs policy adoption.