Objective: This article aims to examine how individual disposition is influenced by group structures and how this in turn enhances team members’ creative and prosocial behaviors. Building on a person-in-situation theory, we argue that altruism is a communal personality leading to the dual outcome of creativity and prosocial behavior, and altruism can best facilitate the dual outcomes of creativity and prosocial behavior when team standardization is low and when team participation is high. Method: Based on data from 346 employees in 86 teams, the results from multilevel modeling largely supported our hypotheses. Results: Altruism is associated with both individual creativity and prosocial behavior when team participation is high. Altruism is associated with individual prosocial behavior when team standardization is low. Conclusions: Our study shows that to foster creativity and prosociality, teams need not only to pay attention to team members’ altruistic dispositional tendency but also to build a participative team environment and reduce team standardization to enable such dispositional tendency to be expressed. In doing so, our study offers a new alignment of prescriptions to foster prosociality and creativity. Being altruistic is an antecedent of prosociality, but it is also a powerful driver of individual creativity in participative teams.