The purpose of this study was to analyse service quality and customer satisfaction by carrying out a comparative analysis between conventional and Islamic banks’ customers in Kenya. The specific objectives of this study were to establish the level of importance that customers attach to different dimensions of service quality and to analyse the level of customer satisfaction with service quality offered by the banks in Kenya. A total of 302 customers were sampled from 2 conventional banks and 2 Islamic banks based in Nairobi County-Kenya. The total sample comprised of 148 Islamic bank customers and 154 conventional bank customers. A descriptive cross-sectional survey design approach was used and structured questionnaires employed for data collection. Data was analysed using the statistical package for social sciences and relationships between and among various independent variables compared using regression, chi square, t tests and correlation analysis. All the service quality dimensions (independent variables) were found to be positively correlated to customer satisfaction (dependent variable). There were strong correlations between customer satisfaction and reliability (rho=0.656), responsiveness (rho=0.607) and assurance (rho=0.567) dimensions of service quality which were significant at p=0.001. Empathy and tangibles, on the other hand, showed a positive though moderate correlation with customer satisfaction which was significant at p=0.001.This implies that an increase in any of the service quality dimension variables would significantly lead to improvement in the customer satisfaction. Overall, conventional bank customers were more satisfied with the service quality offered by the banks more than the Islamic bank customers. This study has shown that banks need to ensure promptness in service delivery as this was found to be a strong predictor of customer satisfaction. Conventional and Islamic banks should also improve on their service quality by providing more sitting space in their banking halls to reduce on congestion, improving on their systems in order to enhance quick transaction processing, improving on their channels of communication and finally reducing their loan processing procedures.