In this study, we explored the mediating effect of affective commitment on the relationship between human resource management practices (HRMPs) and the turnover intentions of university employees in Uganda using the theoretical lens of social exchange theory. The study was instigated by reportedly persistent increase in the cases of employee attrition in higher education institutions in Uganda in spite of Government's attempts to improve the working conditions of the university employees. Using the cross-sectional survey research design, data were collected with the use of an adapted self-administered questionnaire from a sample of 722 academic and nonacademic employees of three public and three private universities in Uganda. The results of structural equation modelling (SEM) indicated that HRMPs were significant positive predictors of affective commitment (rewards: [beta] =0.225; p<0.001), promotions: [beta] =0.228; p<0.001; and job security: [beta] = 0.141; p<0.001). However, HRM practices were negative predictors of turnover intentions (rewards: [beta] = -0.228; p<0.001; promotion, [beta] = -0.215; p<0.001; job security, [beta] = -0.138; p<0.001). Furthermore, affective commitment was indeed a significant mediator of the relationship between HRMPs and turnover intentions of university employees. These findings made us draw the conclusion that when university employees perceive the institution's HRMPs to be favourable, they will not only become committed to the organisation but also desire to remain working longer for it. Therefore, we recommend that the university managers in Uganda and similar countries should formulate and practise human resource management styles that do not only spur employee commitment but also enhance staff retention.