We investigate the link between a firm's leverage and the characteristics of its suppliers and customers. Specifically, we examine whether firms use decreased leverage as a commitment mechanism to induce suppliers/customers to undertake relationship-specific investments. We find that the firm's leverage is negatively related to the R&D intensities of its suppliers and customers. We also find lower debt levels for firms operating in industries in which strategic alliances and joint ventures with firms in supplier and customer industries are more prevalent. Consistent with a bargaining role for debt, we find a positive relation between firm debt level and the degree of concentration in supplier/customer industries.