This paper examines how environmental costs affect the corporate financial performance (CFP) of manufacturing firms around the world. We maintain that by effectively investing in corporate environment responsibility (CER), executives can decrease their firms’ environmental costs, thereby enhancing CFP. We label this argument as the ‘slack resources’ hypothesis. We find that countries in the Asia-Pacific region have the greatest variation between their return on assets (ROA) and environmental cost-adjusted ROA. This comes at the expense of rapid economic development in the emerging economies in the region. We also find that conventional industries such as the basic resources and the food and beverage industries have substantially high levels of total environmental costs, whereas the opposite holds true for the technology and telecommunication industries. Our results suggest that the reduction of environmental costs is related to higher firm performance. We also identify dynamic relations between these two variables. Lowering environmental costs tends to precede the enhancement of ROA by at least two years. Overall, our findings are supportive of the slack resources hypothesis.