Organizational communication is an element of organizational structure formation; it is also a process of achieving organizational goals through the information sharing among the staff members in the organization as a social system. Organizational performance is a multidimensional concept composed of efficiency and effectiveness and satisfaction. Effectiveness implies service quality and the degree of goal achievement. Service quality by using the $LibQUAL+^{TM}$ model can be considered as an objective performance measure for libraries. This study aims to identify the effect of organizational communication in public libraries on service quality as a performance measure using the $LibQUAL+^{TM}$ model through statistical analyses of the results from questionnaire surveys of librarieans and users in 8 public libraries in Seoul metropolitan area. The result says the characteristics of organizational communication(upward, horizontal, downward communication) affects the three elements in the library service quality, such as affect of service, information control and library as place.