This research examines antecedents of trust formation in new product development partnerships and the effect of trust on performance. Trust is modeled as an outcome of communication behavior, shared problem‐solving, perceived fairness, the existence of conflicts during the development project, and partner egoism. The hypotheses are tested with data on 44 product development partnerships representing the perspective of the manufacturer. The findings suggest that communication behavior and fairness are positive contributors to trust. In contrast, conflicts during product development and perceived egoism of the partner appear to have a detrimental effect. High levels of trust were found to create the conditions for successful outcomes. A higher level of trust clearly differentiates between high‐ and low‐performing collaborative relationships in new product development. Trust also was found to be a powerful mediator, particularly as it relates to mitigating conflicts during such partnerships.
