The main goal of this study is the assessment of customer satisfaction and service quality ofrnCommercial Bank of Ethiopia's automated teller service. To this end, user's level of customerrnsatisfaction and their perception of the quality of service being provided by the bank wererninvestigated. To accomplish this, a questionnaire survey was conducted by taking the mostrnimportant ATM service quality dimensions that were identified by several researchers fromrnliterature. The data from the questionnaires were analyzed through mean and standard deviationrnas well as through correlation analysis with the help of SPSS statistical software program.rnAccording to the findings customers found, the ATM service to be exceptionally easy to use andrnhighly secure from fraud. However, responsiveness and reliability of the ATM service werernfound to be low on customer's perception. The major problems faced by customers while usingrnthe service include ATM not functioning all the time, ATM not being able to provide accuraternand consistent services, cash not being available inside the ATMs and ATM network not alwaysrnbeing available, ATM contact person not being available, breakdown of ATMs not being fixedrnpromptly and the recovery speed of the ATM being slow when there is a failure. The findingsrnalso show that all of the selected service quality dimensions have a significant and positivernrelationship with customer satisfaction. When the respondents were asked to rate their overallrnsatisfaction with the ATM service, most of the respondents stated that they were satisfied with thernservice. Finally, this paper will help Commercial Bank of Ethiopia understand what itsrncustomers perception is towards its ATM service. This will in turn help it focus on therndimensions that customers believe its ATM service is performing weakly and which servicerndimensions it should build and improve on. This study only focused on the ATM services of CBErnsituated in Addis Ababa and used convenience sampling method to reach its target population