Based on interviews with facility managers in the electroplating and chemical industries, this study examines regulated firms' perceptions of how various instrumental, normative, and social factors motivated their firms' environmental actions. We found that "implicit general deterrence" (the overall effect of sustained inspection and enforcement activity) was far more important than either specific or general deterrence, and that deterrence in any form was of far greater concern to small and medium-sized enterprises than it was to large ones. Most reputation-sensitive firms in the environmentally sensitive chemical industry chose to go substantially beyond compliance for reasons that related to risk management and to the perceived need to protect their social license to operate. Almost half our respondents also provided normative explanations for why they complied. Overall, we conclude that there are various, often interwoven, strands that must be taken into account in understanding what motivates corporate environmental behavior, and how they play out depends very much on the size and sophistication of companies themselves and on the characteristics of the industry sector within which they are located.