Environmental deterioration has, over the years, produced unpleasant results with effects on health and economic development on earth. These health and economic ills are brought to the fore by pollution, inappropriate waste disposal, deforestation and wildlife extinction, most of which constitute criminal acts or omissions. In the wake of this, criminalizing environmental harm has become the mainstay of environmental legislation in Nigeria and even with the environmental laws and policies targeted at solving the problems, the situation in the country appears to be increasingly added-to, thanks to the weakness of the punitive measures and the sterility of the enforcement agencies in the country. This paper, therefore, scrutinizes the use of environmental law by selected enforcement agencies in Nigeria (federal and state levels alike) to curb environmental harm, prosecute green crimes, the methods of enforcement invoked by these agencies over the years, as well as the perceived challenges encountered in the enforcement of the relevant criminal provisions of the laws. Consequently, this paper proffers pragmatic solutions to the challenges of green crime enforcement in the country.