Markets for endangered species potentially generate incentives for both legal supply and poaching. To deter poaching, governments can spend on enforcement or increase legal harvesting to reduce the return from poaching. A leader–follower commitment game is developed to examine these choices in the presence of illegal harvesting and the resulting impacts on species stocks. In addition, current trade restrictions imposed under the Convention on International Trade in Endangered Species of Wild Fauna and Flora are examined. With Cournot conjectures among poachers, the model details the subgame perfect equilibrium interactions between poaching levels, enforcement and legal harvesting.