This study examines the antecedents of supply chain project success. We first propose and test a model that describes the role of relationship-level factors (trust and asymmetric dependence) and project-level factors (between-firm communication and within-firm commitment) in determining supply chain project success. We find that project-level factors completely mediate the effect of trust on project success. We conclude that trust, despite being a stronger predictor compared to asymmetric dependence, is necessary but not sufficient for supply chain project success. We then proceed to further explore the role of these factors by introducing a categorical scheme that differentiates supply chain projects based on the decision rights configuration of each project. This categorization enables us to explore how relationship-level and project-level factors can have different impact on performance based on the characteristics of a supply chain project. The findings offer insights into how to effectively manage supply chain projects and inter-firm alliances.