Knowledge, as a source of firm's competitive edges, has been drawing attention, while numerous enterprises are investing huge amount of assets to foster the right environments for executing knowledge management (KM). As a practical way of such KM, knowledge management systems (KMS) support the creation, diffusion, and utilization of knowledge, which are the tools for practicing such management style. Recently, the customer centers which make the closest contact with the customers are being concerned about the establishment of KMS. Considering the characteristics of real-time problem solving in customer centers during the consultation with the customers, the importance of KMS is paramount to the centers. This study analyzes major factors influencing the success and utilization of the customer center KMS's reestablishment, as an exploratory case study of the reestablishment of KMS in the customer center of K insurance company. First, the characteristic differences between the customer center's KMS and the traditional KMS are discussed, and the triangulation technique is applied to secure objectivity of this case study's findings. Major results of the case study state that, for the success of KMS and improvement of utilization, the followings should be considered preferentially: excellent system quality (accessibility, user convenience, easy searching, speed/menus); high information quality (accuracy, usefulness, timeliness, task-relevance, diversity, degree of specification); appropriate operation strategy and process for the utilization of system (education, training opportunity, appropriate personnel, speed and procedure of approval, compensation/evaluation); and change management via the support from the CEO's level (concern and participation of CEO, will to propel the project, investment, advertisement, etc.). This study provides practical suggestions with respect to factors which should be more carefully dealt with, since still many customer centers have hard time establishing and operating KMS due to lack of previous studies.