In order to explore its many complexities, scholars have called for a move beyond, descriptions of sustainable procurement. This study responds by seeking insights into sustainable procurement through the lens of social capital theory. Social capital is conceptualized as comprising cognitive, social and relational elements. Sustainable procurement is seen as a means of pursuing environmental, economic and social goals through the purchasing and supply process. The study, proposes and empirically tests the operational measures of social capital and their relationship with, sustainable procurement activity on a sample of 135 procurement professionals in organizations, providing social housing. The results indicate partial support for the study proposition; structural, social capital, rather than structural, social and relational taken together, is found to be the most robust predictor of sustainable procurement. The results highlight the importance of broadening, collaboration models for sustainable procurement beyond an exclusive focus on dyadic relations. It, also demonstrates that this broader engagement with other stakeholders focused on knowledge creation, as well as knowledge sharing, is a significant contributor to sustainable procurement activity.