The present research examines the relationships between progressive HRM practices and the organizational citizenship behaviors (OCB) of professional employees. Drawing on recent HRM literature, our research model includes a perceived organizational support (POS)-commitment mediation hypothesis. Taking into account previous studies on professional employees, a job satisfaction-commitment pathway is also integrated. We tested both mediational pathways as part of a single structural equation model using a sample of 329 professional employees. Our results show that the relationship between recognition and OCB is mediated by the POS-commitment pathway, while the relationships between fairness of rewards, skills development and OCB are mediated by the job satisfaction-commitment pathway. The specificities of the HRM of professional employees related to their multiple cognitive orientations are discussed.