The majority of water service boards are investing millions of money in different portfolios with the objective of profit maximization. However, delays in projects are a global phenomenon and have become a typical part of the project manager’s concern. Therefore, the purpose of this study was to determine the influence of project portfolio management practices on the performance of water service boards in Kenya. The specific objectives of the study were; to determine the effect of project evaluation, project selection, and prioritization, to establish the moderating effect of contextual factors on the relationship between project portfolio management practices and performance of water service boards in Kenya. The study adopted a crosssectional survey research design. The population of this study targeted the employees of water boards in Kenya which include coast water service board (CWSB), Rift valley water service board (RVSB), Lake Victoria North (LVNSB), Tana water, Tana Athi water service board, Athi water service board. The unit target constituted Engineers, senior management, middle management, and project team.