Social orientation refers to the extent to which members of an organization are provided with opportunities to have private social contacts and activities outside their work settings. Based upon social interaction and communication flows perspectives, the present research constructs a model depicting the relationships among social orientation, organizational citizenship behavior, R&D-marketing collaboration, and the process performance of new product development program. The empirical results support most hypotheses posited by the authors. In particular, the relationship between social orientation and R&D-marketing collaboration is found to be mediated by organizational citizenship behavior (i.e., helping behavior and civic virtue), and social orientation has no direct effect on the collaboration.