A Research Report Submitted to Mzumbe University - Mbeya Campus College in Partial Fulfillment of the Requirements for the Award of the Degree of Bachelor of Human Resources Management (BHRM) of Mzumbe UniversityThere is widespread dissatisfaction with service delivery, because of difficult to measure the level of customers’ satisfaction as well as to understand the factors that influence it, despite an abundance of research on customer service, and customer satisfaction, limited empirical evidence exists regarding context specific situations. This research report was emphasis mainly at the assessment of customer satisfaction in service delivery by TRA to its customer in Dar es salaam, basing on the five dimensions of Serviqual model, which include reliability, responsiveness, assurance, empathy and tangibility. Kind of research design used was case study survey design. The study was carried out at TRA Dar es salaam regional office in Dar es salaam. During the survey, the researcher used questionnaires to get information from TRA staff and from individual and corporate customers located at different places in Dar es salaam. The questionnaires were designed in two categories, namely; TRA staff questionnaires and TRA customer’s questionnaires the research used primary and secondary data. Primary data was collected through survey questionnaires tool from TRA customers’ and TRA workers at Dar es salaam region. The questionnaires collected from respondents were 93 out of sample size of 100 respondents as described on table 3.1. Simple random sampling techniques were used to select respondents for the study. The searcher applied SPSS for data analysis before giving interpretation and discussion. The first specific objective was to identify kinds of services provided by TRA in Dar es salaam and, 69.2% of respondents were able to identify kinds of services provided by TRA in Dar es salaam table 4.10. The second specific objective was to Assess CS on Service delivery by TRA. TRA Customers were satisfied with the services delivery by TRA in Dar es salaam basing on Serviqual dimensions table 4.10. The third specific objective was to determine the factors, which influencing CS. It was concluded that the most important ingredient in the delivering of service to taxpayers like any other places, are the five dimensions of Serviqual model. The researcher recommendations were that; TRA is contrary to other service organization since the organization is dealing with different customers /taxpayers in different aspect while there no direct value in exchange in kind of services, hence TRA could not perform well collecting more taxes without customer care. Collection of more taxes is not the only measure for efficiency unless coupled with good customer care.