The debate on whether legalization or prohibition is more effective in conserving species and curbing illicit black-market trade remains controversial, with insufficient evidence available. Here we investigate the effects of China's ivory ban on elephant poaching. We find that the enaction of the total ivory ban corresponds with a sharp 50% decrease in poaching and a significant reduction of the number of seizure cases. Further, although China has taken restrictive measures in 2015 and signaled a total ivory ban in 2016, no occurrence of "last minute rush" in smuggling activity was found preceding the implementation of the ivory ban.