The relationship between HRM practices and service quality is still fuzzy as previous studies did not pay much attention to the mechanism that explain the relationship between HRM practices and service quality. This lack of attention makes the understanding of how HRM practices associate to service quality is limited, in particular in the underdeveloped countries such as Yemen. Therefore, the aim of this study was to examine the mediating effect of organizational commitment, job satisfaction, and job involvement in the relationship between HRM practices and service quality. The data for this study was collected through questionnaires. The sample was 247 academic staff and 1235 students in University of Aden, Yemen. The data of this study was analysed using a Structural Equation Modelling technique. The findings show that HRM practice has important role on service quality, organizational commitment, job satisfaction, and job involvement. In addition, organizational commitment, job satisfaction and job involvement play an important role in service quality, and partially mediate in the relationship between HRM practices and service quality. Theoretical and practical implications, limitation, suggested and directions for future research were included in this study.