Workplace friendships are primary sites of organizing associated with important outcomes including cohesive climates, creativity and innovation, and employee job satisfaction. Research indicates the workplace context influences the initiation of workplace friendships via physical proximity and shared projects. The present study demonstrates how another context variable – perceived task interdependence (PTI) – influences both the initiation and the continued development of workplace friendships into closer levels. The links between PTI and workplace friendship were examined, centering on communication (frequency and channel) and trust as mediating variables. PTI was associated with both the initiation and development of workplace friendships. Moreover, the link between PTI and friendship closeness was fully moderated by communication and trust. Results also demonstrated that asymmetric PTI (i.e., one coworker is more/less dependent on the other) influenced trust, but only for non-friend coworkers. Friendship appears to buffer the relationship from potential negative effects of asymmetry.