This study investigates the role of institutional pressures in corporate environmental responsibility (CER) by testing the interacting effects among cognitive, regulative, and normative pressures at cross levels. Specifically, this research decomposes the cognitive dimension of CER into perceived environmental benefit and perceived ethical obligation to differentiate their mechanisms. The sample is obtained from 212 firms within 34 industrial clusters. Results of two-level regression modeling confirm that regulative and normative pressures play different roles in the positive effects of perceived environmental benefit and perceived ethical obligation on CER. Regulative pressure attenuates the effect of perceived environmental benefit and amplifies the effect of perceived ethical obligation. Meanwhile, normative pressure attenuates the effect of perceived ethical obligation. These findings suggest that heterogeneous interaction effects may reduce the efficiency of institutional pressures during the initial stage of CER diffusion. Implications for future research and policies are discussed.