This study was motivated by the need to establish the factors which prevent and affect customer retention in Micro Financial Institutions using Amhara Credit and Saving Institution Simada Branch as a case study which was found in Simada District of Amhara Regional State. To achieve this objective, the study used a co relational research design which resembles descriptive and explanatory design and has the ability to describe things as it is and explains the relationship between two or more variables. Data was collected from the customers of Amhara Credit and Saving Institution Simada Branch using self administered structured questionnaires. The quantitative data collected was checked for completeness, coded and entered into a computer for analysis. The data was analysed using descriptive statistics with the aid of a computer software SPSS. The study found that customer retention is positively influenced by customer satisfaction, interpersonal relationship, interest rate fairness and accessibility of financial services. Further findings indicated that customer retention in banks is also influenced by the corporate image of the banks based on the stability, familiarity and reliability. The study recommends management puts strategies so as to satisfy their customers and to retain them and prevent them from going to other similar service providers. It also recommends that Amhara Credit and Saving Institution put in place a customer retention team to monitor and address issues contributing to customer attrition.