In this study, one of the private insurance services companies in Iran is considered as a case study to investigate its customer’s satisfaction and retention rate. In this regard, and for the first time in the case company, the auto insurance was investigated in two different time periods. Results indicated that more than 30% of the company's customers in this scope did not renew their auto insurance in the case company. The reasons that the customers were lost are investigated and listed in this step. Afterwards, by using Cochran's test, 567 and 599 samples were selected randomly for the first and the second phases, respectively. After contacting the customers through a phone call, it was deduced that "the sale of insured car" was the main reason of losing customers in this scope. "The impossibility of making a call or having a wrong number" and "customers gravitation toward other agencies of the same insurance company" are the two other reasons that customers abandoned the mentioned company. The results of this study, which is conducted for the first time in one of the main insurance companies in Iran, can be useful for similar insurance companies who want to improve their customer satisfaction.