This study sought to examine the challenges facing the implementation of photovoltaic power plants in NairobiCounty. This study used a descriptive research design. The target population of this study was 123 project managers in photovoltaic power plants' projects in Nairobi County. The sample size was determined using Slovin's Formula. This study used of both primary and secondary data. Quantitative data was analyzed by use of both inferential and descriptive statistics with the help of statistical software known as Statistical Package for Social Sciences (SPSS version 22). The study found that project planning has positive and significant effect on implementation of photovoltaic power plants in Nairobi County. The study also established that project funding has positive and significant effect on implementation of photovoltaic power plants in Nairobi County. Moreover, the results revealed that project management skills have positive and significant effect on the implementation of photovoltaic power plants in Nairobi County. Further, the study found out that project leadership has positive and significant effect on implementation of photovoltaic power plants in Nairobi County. The study recommended that project managers should avail all work related items, develop necessary task procedure and set time to review work progress so as to implement photovoltaic projects on schedule. In addition, the study recommended that the projects managers should seek for financial resources through application of grants, donations and enhance their venture capital so as to ensure adequate financial resources available for purchase materials and cater for miscellaneous expenses. Further, the study recommends that the management of photovoltaic projects in Nairobi County should come up with appropriate training, career development and talent attraction programmes so as to enhance project managers' competency skills. Furthermore, the study recommends that the project managers in Nairobi County should tie bonuses to projects, reward staffs that meet their goals and provide heartfelt appreciation as a way of improving on photovoltaic projects' rewarding schemes.