This study aimed to evaluate the service quality of the Registrar's Office at Kotebe University of Education in Addis Ababa, Ethiopia. The researcher used an explanatory sequential design with a mixed method of research approach. Service quality model questionnaires and interviews were administrated to gather data. The collected data was analyzed using SPSS and various statistical techniques. Qualitative data obtained from the semi-structured interviews were analyzed and coded thematically. This study used linear regression models to examine how various aspects of service quality affect customer satisfaction with the University's Registrar. The findings show that assurance, tangibility, reliability, responsiveness and personal interaction have positive effect on members’ satisfaction whereas empathy does not. The analysis of linear regression result indicated that the R2 value is 0.5408, i.e. the independent variable of service quality and explained 54.1% of the variation in customer satisfaction, indicating a moderate impact.However, the qualitative data and document analysis results confirmed that the provision of service quality didnot satisfy students' expectations. Based on the findings, the study concludes that, overall, the Registrar's office's performance not pragmatic to  meet customers’ expectations. Based on this, the study recommends that the office makes efforts to improve its services and ensure customer satisfaction.