The role of local government institution and especially institutional structures and political culture often shape government performance including livelihood supporting activities such as Urban Agriculture (UA). The changing population pattern orchestrated by the spread of urbanization has resulted into a rise in poverty and food demand, necessitating UA. However, there seem to be limited documentation with regard to how local governance institutions influence and promote UA practices. The purpose of the study was to assess how roles of local governance institutions influence promotion of urban agriculture practices in Western Kenya. The specific objectives were to investigate the influence of economic, social and environmental roles of institutions, and the relationship between county government institutions roles and urban agriculture practice. Cross sectional survey design was adopted on a target population of 440 urban farmers (Eldoret: N=137; Kakamega: N=145; Kisumu: N=158) identified through the assistance of County Agricultural officers in the three towns. A sample size of 205 respondents (Eldoret=63; Kakamega=68; Kisumu=74) was obtained using stratified technique. Questionnaire and Key Informant interviews were used for data collection. Inferential statistics using Pearson Product Moment Correlation Coefficient was used in data analysis. Results showed that the department of agriculture, livestock and fisheries was the most important institution on promotion of urban agriculture in Kisumu (40.0%), Kakamega (42.2%) and Eldoret (64.8%). There was there was a moderate positive correlation (n=205; r =.532; p <.05) between role of county government institutions and UA practices which was statistically significant.