Purpose-The main purpose of this study is to assess the most important factors (dimensions)rnaffecting customersâ€™ satisfaction in Automated Teller Machines (ATMs) service of United BankrnS.C.rnDesign/methodology/approach- The study employed a quantitative methods based on arnconvenience sample consists mainly of respondents in different professions at the age of abovern18 years. Self-administered questionnaire, which consists of demographic characteristics andrnsurvey questions both in Amharic and English, was distributed to 379 United Bank ATM users.rn20 ATMs were conveniently selected in order to reach ATM users in different parts of AddisrnAbaba. Instrument development was based on reviewing related literatures and discussing withrnconcerned academicians and practitioners in the area of ATM service and customer satisfaction.rnFindings- The researcher finds out that convenience, empathy, tangibility and speed are thernmost significant customer satisfaction dimensions of ATM service in United Bank S.C.rnResearch limitations/ Implications- the study employed convenience sampling technique tornchoose sample respondents who are ATM users of United Bank in ATMs located in Addis Ababa.rnThe non-probability sampling technique was employed due to lack of access to customersâ€™ listrnbecause of the bankâ€™s policy. The sample was taken only from Addis Ababa and may notrnrepresent the entire ATM service customers of United Bank S.C.rnPractical implications- UB Managers in all levels will be benefited from the findings of thernresearch in order to better off ATM service quality and increase customer satisfaction throughrnapplying the identified service quality dimensions.rnOriginality/Value- The research is one of the few original studies in the area of ATM servicernparticularly in the assessment of the important dimensions affecting customersâ€™ satisfaction