This work reviews two environmental enforcement systems, the Chilean and the American, from a comparative-functional perspective. After reviewing hundreds of cases, the study revealed that in Chile there are important deficiencies at the policy level, which are then reflected in the result of particular cases. On the other hand, the American enforcement system shows no deficiencies at the policy level, but when it comes to practice, it is not possible to discern if policies are actually–and correctly–applied in particular cases. This is relevant because any fair reading of the major US environmental statutes suggests that penalties should incorporate explicit assessments of the respective penalty factors. This raises rule of law and transparency concerns. At the end, by way of conclusion, it is suggested that both the Chilean and the US environmental enforcement systems would be better if they adopted specific strengths of the other.