Based on expectancy theory, goal-setting theory and control theory, we propose a model in which perceived fairness mediates the relationship between characteristics of employee performance management (PM) systems and their perceived effectiveness by employees. PM system characteristics we propose are the frequency and length of formal reviews, the frequency of informal reviews and feedback, whether the formal conversation focused on evaluation or development and finally the degree of participation. The model was tested on a cross-industry sample of 3192 employees in Belgium. The measurement and structural models were simultaneously tested using structural equation modeling, and we used a bootstrapping approach to test the mediation hypothesis. Our findings indicate that performance review focus and employee participation strongly relate to perceptions of appraisal fairness and PM system effectiveness and that the frequency of informal performance reviews is stronger related to PM system effectiveness than the frequency of formal performance reviews. This suggests that the manifest expressions of PM have more impact on PM system effectiveness rather than the more latent characteristics of PM systems. The findings advance research to the role and functionality of PM systems by showing that (a) the manner in which PM systems are shaped and executed is of fundamental importance for their effectiveness, (b) fairness partially mediates the relationship between PM system characteristics and their effectiveness and (c) the three motivational theories appear useful for understanding the consequences of PM practices on individual employees.