This study empirically examines the influence of organizational culture on supplier diversity. It examines the relationship between buyer behavior and culture using the Organizational Culture for Diversity Inventory (OCDI). The research assesses 12 business units within a heavy equipment manufacturer and uses confirmatory factor analysis to test an explanatory model of supplier diversity effectiveness. Results indicate achievement and affiliative culture styles are important to the effectiveness of supplier diversity. Moreover, in business units characterized by defensive or passive–defensive cultures, minority sourcing was lower. Conversely, the business units with constructive cultures for diversity had higher minority sourcing.