The widespread introduction of genetically modified (GM) crops may change the effect of agriculture on the environment. The magnitude and direction of expected effects are still being hotly debated, and the interests served in this discussion arena are often far from those of science and social welfare maximization. This chapter proposes that GM crops have net positive environmental effects, while regulatory responses focus mainly on environmental concerns, giving an unbalanced picture of the regulatory context. This unbalance supports the hypothesis that environmental concerns about GM crops have been politically instrumentalized and that more attention should be paid to regulatory responses considering the environmental benefits of this technology. It is also argued that a number of environmental effects have not yet been quantified and more research is needed in this direction.