The Constituency Development Fund was established in Kenya in 2003 with a view to addressing regional imbalances and empowering communities to prioritise and manage development projects at the grass root. This has made significant contribution in bringing essential services to the grass root. Many complaints have however been lodged by constituents with regard to performance of projects as a result of poor choice of projects, poorly constructed projects, stalled projects and projects that are completed but not in use. In the years 2013/2014 to 2015/2016, the National Government allocated a total of Kes 86.8 Billion to all the constituencies with Ruiru constituency being allocated Kes 279 million to finance different projects in line with CDF Act. Different researchers have investigated various factors that affect the performance of NG-CDF funded project. The objective of the study was to investigate the effect of project selection criteria on performance of NG-CDF funded projects in Ruiru Constituency, Kiambu County, Kenya. Project cost, time to completion and quality of the outcome have been noted to be the most visible and significant indicators of project performance due to the objectivity that characterizes their measurement and their direct economic implications if they are exceeded. The specific objectives were to investigate the effect of alignment with strategy, community participation, capacity to implement projects and feasibility of the project on performance of NG-CDF funded projects in Ruiru constituency in Kiambu County. The study was anchored on the theory of constraints, strategic alignment theory and theory of rational choice. The study employed a quantitative design using descriptive and inferential statistics to collect and analyze data and make inferences on the effect of selection criteria on performance of projects. The study’s units of analysis were 91 CDF projects, in Ruiru constituency in education, water, health, transport, environment and social services sectors that were approved between 2013/2014 to 2015/2016 financial years. The units of observation were 131 representatives comprising of a member of the executive of constituency committee and project management committee, an ordinary member of each of these committees, officers in charge of ministries of education, water, health, transport, environment and social services at sub county level. Data was collected using a questionnaire and an observations checklist. The relationship between the variables was determined through descriptive statistics, regression and correlation analysis using the Statistical Package for the Social Sciences (SPSS) version 21. The researcher used test retest test reliability of the questionnaire. The research established that, the independent variables alignment with strategy (X₁), feasibility of project (X2), capacity to implement projects (X3) and community participation (X4) affected performance of projects with aggregate mean scores of 3.46, 3.42, 3.31 and 3.31 and Pearson correlation values of r= 0.515, r=0.736, r=0.765 and r=0.679 respectively. The regression model had an R Square value of 0.661 inferring that they explained 66.1% of project performance. However, it was established that the constituency did not have a strategic plan making coordination of development efforts disjointed. There were instances of projects that could not be identified on the ground, Poor documentation of project approvals and dissemination of information to stakeholders making it difficult to track projects absence of schedules and budgets hence no benchmark for measuring progress of cost and timelines. Many of the people charged with managing the projects lacked qualifications making it difficult to make appropriate judgments and there were many instances where communities were not involved in project management processes. Researcher recommends that there should be deliberate effort to align project objectives with organisation strategy, CDF funded projects must be evaluated to establish their feasibility, Constituency must build capacity to implement projects and community should be sufficiently involved in project identification and prioritisation. The CDF Act should be improved to ensure a more rigorous process of project identification, selection, evaluation and approval with minimum thresholds to be met before a project is accepted for funding. Further research should be undertaken on how to link project management with organisation strategy with particular reference to CDF funded projects.