A critical question is what leads some companies, but not others, to be sustainable in their procurement operations. Some studies respond to this question using various theoretical frameworks. However, these frameworks, while valuable, do not fully reflect the nuances of decision-making in procurement operations. The theory of planned behavior (TPB) is recognized as the most influential framework for predicting behavior but its application in operations management is hitherto limited. We aim to illuminate the role of individual attitudes, capabilities, and behavioral intentions in actualizing sustainable procurement. We develop a framework by adapting TPB to the context of sustainable procurement. We test this framework with a sample of 465 procurement professionals based in the EU through partial least squares structural equation modeling. We find that sustainable purchasing behavior is predominantly shaped by behavioral intention, that is, willingness to pay for sustainability. This behavioral intention is significantly influenced by individual attitudes and capabilities in addition to awareness of consequences and corporate social responsibility engagement but, interestingly, not by subjective norms. The present study contributes to understanding individual-level antecedents of operations management practices and offers suggestions to practitioners engaged in fostering sustainability in supply chains.