This paper examines the influence of financial and non-financial performance measures on perceived Islamic banks’ service quality in the United Arab Emirates. External customers and internal customers of Islamic banks were considered in the study. External customers represent individuals dealing with the banks and their sample consisted of 230 customers. Internal bank customers represent banks’ employees with a sample size of 174 participants from five main Islamic banks in UAE. Data were collected mainly through a questionnaire and analyzed and tested through two proposed models using structural equation modeling techniques. The results indicate strong positive relationship between service quality and banks’ performance and that banks internal operations mediate the relationship for the external customers group.