Municipal solid waste management in Kenya has remained a challenge despite being devolved to forty-seven regional Counties in 2010 resulting in ongoing negative impacts on human health and environment. The study sought to investigate the success of Kitui County government in managing municipal solid waste with an aim of producing recommendations for its improvement. The research adopted mixed method approach and the research data was obtained through key informant interviews and issuance of survey questionnaires. Kitui municipality manager, Kitui municipality environment, recreation and social services director, municipal solid waste management supervisor, Kitui County National Environment Management Authority (NEMA) director, and Kitui County environment director were purposively selected as key informants for this study. The interview data obtained was descriptively analysed by looking at common themes arising from the interview narratives. Insights from the interview data revealed that financial constraints, and limited knowledge on sustainable municipal solid waste management practices, policies and regulations among Kitui municipality residents were some of the factors contributing to unsustainable municipal solid waste management practices in Kitui County. Randomly sampled (399) Kitui municipality residents were enrolled in a questionnaire survey on their experiences with Kitui County waste management operation. Of the 399 questionnaires issued 390 were completed and returned. Data obtained from the survey questionnaires was descriptively analysed by determining variable frequencies and presented in pie charts, bar graphs and frequency tables. The study findings revealed that, 42.8 % of the respondents were not satisfied with how Kitui County government undertakes waste collection exercise. Additionally, 23.8% of the respondents lacked waste collection services with 61% of them undertaking open burning of their generated waste. Waste from 31.2 % ...