BACKGROUND: While evidence-based recommendations for the management pneumonia in under-5-year-olds at the community level with amoxicillin dispersible tablets (DT) were made by the World Health Organisation, initiatives to promote the integrated community case management (iCCM) of pneumonia through the proprietary and patent medicine vendors (PPMVs) have been poorly utilized in Nigeria, possibly due to low financial support and perceived benefit. This study provides costs, benefits and cost-effectiveness estimates and implications of promoting the iCCM through the PPMVs' education and support. The outcome of this study will help inform healthcare decisions in Nigeria. METHODS: This study was a cost-effectiveness analysis using a simulation-based Markov model. Two approaches were compared, the 'no promotion' and the 'promotion' scenarios. The health outcomes include disability-adjusted life years averted and severe pneumonia hospitalisation cost averted. The costs were expressed in 2019 US dollars. RESULTS: The promotion of iCCM through the PPMVs was very cost effective with an incremental cost-effectiveness ratio of US$143.77 (95% CI US$137.42-150.50)/DALY averted. The promotion will prevent 28,359 cases of severe pneumonia hospitalisation with an estimated healthcare cost of US$390,578. It will also avert 900 deaths in a year. CONCLUSION: Promoting the iCCM for the treatment of pneumonia in children under 5 years through education and support of the PPMVs holds promise to harness the benefits of amoxicillin DT and provide a high return on investment. A nationwide promotion exercise should be considered especially in remote areas of the country.