Who blames corruption for the poor enforcement of environmental laws? The answer to this question is important since corruption is an important reason why environmental policies are not properly enforced, but previous studies of environmental public opinion do not address the issue. We analyze data from a survey fielded in Brazil in June 2012, immediately preceding the Rio+20 environmental summit. We test hypotheses on income, education, and perception of corruption as a cause of poor enforcement of environmental policy. We find that wealthy individuals are more likely to associate corruption with enforcement failure than their poorer counterparts. However, education is not associated with the belief that corruption is a primary cause of enforcement failure. These results suggest that since wealthy Brazilians have a higher exposure to corruption because of their interaction with government officials, they understand the role of corruption in policy failure. Conversely, the kind of general information that education offers does not raise concern about the role of corruption in environmental policy. The results have important implications particularly in democratic societies, where governments have stronger incentives to address the problem if the concerned public associates corruption with enforcement failure.