Citizen Participation is one of the national values and is also a principle of public service. Moreover, quality of participation in financial matters both at the national and county levels is necessary to inform decision making and resource allocation. This study examined the factors affecting public participation in budgeting process in the County Government of Nandi. The study was guided by the following specific objectives: to determine whether public participation forums affect budgeting process; to determine whether stakeholders’ involvement affects the budgeting process and to establish whether socio-cultural factors affect public participation in the budgeting process in the County Government of Nandi. The study was guided by agency theory, games theory and public choice theory. The study adopted a descriptive survey design targeting 75 Community Based Organizations (CBOs) members who are residents of County Government of Nandi, 5 CBO officials and 5 officials from the Treasury and Economic Planning department in the County Government of Nandi. Stratified random sampling technique was used to select members of the stratus of the identified Community Based Organizations who were administered with structured questionnaires, while key informants CBO officials and officials from the Treasury and Economic Planning department were chosen through purposive sampling.