Electronic tax service is one of the most useful instruments to increase productivity and revenue of government and taxpayers. Despite these, however, only small numbers of taxpayers are using the service and others in Addis Ababa found to be reluctant to use electronic tax service. Therefore, the study was focused on assessing the factors that affect taxpayers’ adoption for etax service in west, east and large taxpayers in Addis Ababa. The total population in the selected three branches was stratified in to two strata (e-tax adopters and non-adopters). Then two stage sampling was employed to select sample respondents. Results are based on data collected from questionnaires of 208 out of 18030 randomly selected taxpayers. Descriptive statistics and probit regression methods were employed. The result shows that perceived usefulness, perceived risk, self-efficiency and timeliness were significant factors of taxpayers’ adoption for electronic tax service but subjective norm is insignificant. Tax authorities and concerned parties should do on expanding electronic tax service by create access to other branches to adopt the system and as the e-tax service is effective and productive in the three branches (west, east and large taxpayers) in Addis Ababa, government should create awareness to other branches.