We investigate the capital structure implications of corporate environmental liabilities, which are captured using the amount of firms’ toxic production-related waste. We document that firms with higher environmental liabilities maintain lower financial leverage ratios, suggesting that environmental liabilities work as a substitute for financial liabilities. The substitution effect is more pronounced for larger firms, firms covered by more analysts, firms that have higher sales to principal customers, and firms with greater community concerns. Further analysis shows that less environmentally responsible firms have a lower fraction of bank debt in total debt, all else equal, consistent with the notion that banks are more environmentally sensitive than other lenders. Overall, our findings imply that being environmentally responsible can enhance firms’ debt capacity and improve the availability of bank credit.