On the basis of social exchange theory, this study examines the impact of two Human Resources Management (HRM) practices, communication and participation, on employees’ perception of psychological contract fulfillment (PCF) and affective organizational commitment (AC). Furthermore, PCF is proposed as a mediating variable between HRM practices and AC. Data from 87 Norwegian organizations and 1055 employees was analyzed using multilevel regression analysis. As hypothesized, communication and participation were linked to employees’ AC. Unexpectedly, only communication was linked to PCF, while participation was not. A mediation effect of PCF was found to link only communication and AC. This study makes a contribution to psychological contract research, by being one of a small number of studies to empirically examine particular HRM practices as antecedents to PCF. Implications for practice are discussed.