In many organizations, the role of purchasing is in a transition from a reactive order taker, into a proactive and internally integrated business partner. Building on a Resource-Based View and Capability-Based View, this study explores how purchasing professionals’ involvement and proactive efforts in sourcing processes affect sourcing project outcomes, in terms of both value creation and supply risk reduction. The authors gathered data on 112 sourcing projects from a large, private financial services company with in-depth and structured interviews with key stakeholders. A structural model deploying the research hypotheses was analyzed using the Partial Least Squares technique. The results reveal that, driven by early involvement of and responsibility granted to the purchasing professional, purchasing proactivity enhances value creation and supply risk reduction sourcing outcomes. Specifically, proactivity mediates the effect of purchasing's involvement on value creation. This study empirically establishes the importance of purchasing proactivity, serving as critical capability of purchasing professionals. Following a dyadic logic, this impacts industrial marketers. More specifically, when purchasers build capabilities to show proactive behavior to enhance value creation and risk reduction, marketers need to develop capabilities to facilitate purchasers in their endeavors.