Abstract: The main aim of the study was to establish the effects of women involvement in decision making on the performance of county: a case of Kiambu county. The study was guided by three specific objectives which included to identify vocational training opportunities for women that will enable them to attain leadership positions, to identify knowledge gaps in women to enable them participate in running the affairs of Kiambu county and to enact relevant policies that would accelerate implementation of agreed global and regional committees of Gender Equality and Women Empowerment (GEWE) in Kiambu county. The study sought to bridge the existing knowledge gap on the effects of women involvement in decision making on the performance of county. Simple random sampling technique was used whereby subjects were selected from the population. Out of a total population of 50,000, a sample size of 400 respondents was selected for the purpose of the study. Questionnaires were used to collect primary data while the secondary data was collected through review of published documents and text books. The presentation of data was through pie charts. The findings from the study indicate that level of education, position in management, advocacy for women leaders, current leadership and marginalization of women leaders affects the participation of women in leadership affairs of their county.