The objective of this study was to establish the mediating effect of service quality on the relationship between CRM and satisfaction of commercial banks account holders in Nairobi City County, Kenya. The study adopted a cross-sectional research design involving descriptive and explanatory research techniques. The target population was 34,649,583 account holders out of which a sample of 400 respondents was selected using mixed sampling techniques. Data was collected using a semi structured questionnaire and analyzed using both descriptive and inferential statistics. Simple and multiple linear regression were conducted to assess the relationships between the variables. The study was limited to a few constructs, cross sectional data, localized population and self reporting. The study established that service quality had a statistically significant mediating effect on the relationship between CRM and satisfaction of commercial banks account holders. The study recommends that commercial banks management should consider service quality dimensions when developing strategies because they have a significant effect on account holder satisfaction with commercial banking services. Commercial banks in Kenya and the central bank can use the findings of this study to formulate CRM related policies that enhance service quality and satisfaction of account holders. To increase the level of generalizability and objectivity, future studies should be carried out in microfinance banks, Savings and Credit Organizations using additional variables and a different methodology. Keywords: Customer relationship management, Service quality, Account holder satisfaction, Commercial banks DOI : 10.7176/EJBM/11-9-07 Publication date :March 31 st 2019