The existing research literature suggests that six main factors influence the collaborative behavior of workers. Collaborative behavior has a crucial impact on the thriving of an organization and its human capital, being a necessary condition for motivating workers to share and exchange their knowledge. The relevant factors are: the workers’ identification with the organization; self, means and external efficacy; human resource management practices; perceived organizational support. While previous studies have dealt with these factors as sub-groups, the current study proposes and tests an integrative model that combines all of them, and adds a new factor: employment contract. The model was validated on IT workers from several sectors.