Research report Submitted to Mzumbe University – Mbeya Campus College in Partial Fulfillment of the Requirements for the Award of the bachelor Degree of Accounting and Finance in business sector (BAF-BS) of Mzumbe University.The study focused on examining the determinants of sim banking performance, the case study of CRDB Bank Plc Azikiwe Branch in Dar Es Salaam. Sim banking is one of the electronic banking product which was launched by CRDB bank Plc in February 2012. The study was carried out successfully by examining the following specific objectives namely (1) to assess the extent to which the customers were aware of electronic banking (2) to assess the impact of preference on the use of sim banking, and (3) to assess the effectiveness of marketing strategies employed to increase the sales of sim banking. One of the CRDB Bank Branch in Dar Es Salaam was purposively selected that is Azikiwe branch, which is a major branch allocated at CRDB Bank Plc head office Posta. Therefore, for the purpose of this study the sample of 67 customers out of 200 population and branch Management staff was drawn to represent CRDB bank customers and Management respectively. The main tools of data collection for the study were questionnaires for CRDB Bank customers and interview for CRDB Bank Management staff. The findings from the study indicated that customers were aware of the existence of electronic banking. However, it was found that the preference as one of the determinants examined had a greater influence on the use sim banking and therefore affecting the sales. It was also found that the fraudulent events so far reported and non-assurance of security were the one of the factors leading to low sales of sim banking despite its large number of customers. The findings also suggested that the marketing strategies were ineffective. The study therefore came up with two major recommendations. First, CRDB Bank Plc should review its marketing strategies in place to ensure all newly introduced products are closed monitored. Second the advantages of sim banking as an electronic product should be clearly communicated to the customers to avoid distortions as a result of rumors from the lay men in the market.