This study sought to explore the effect of interpersonal factors such as workplace friendship, team-member exchange (TMX), and leader-member exchange (LMX) on organizational citizenship behavior (OCB). Results from a sample of 325 participants recruited through Amazon's Mechanical Turk showed that-contrary to expectations-LMX and TMX were associated more strongly to OCB towards the organization than to OCB toward individuals. Results also supported the predictive effect of workplace friendship on TMX, and also the predictive effect of LMX on workplace friendship. Finally, the findings indicated that TMX fully mediated the relation between workplace friendship and OCB, while workplace friendship only partially mediated the relation between LMX and TMX. Theoretical implications and limitations of the results, as well as directions for future research are discussed.