The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) is the international agreement that regulates international trade in wildlife to prevent its decline. Little is known about the effectiveness of its trade restrictions and bans. Combining the largest available panel database on wildlife population sizes of vertebrates with the history of species’ inclusion into CITES, we find that populations increase by 20% after their species’ inclusion into CITES. This effect is driven by populations in countries with thorough enforcement. Outright trade bans increase wildlife, but restrictions that incentivize sustainable use have more immediate positive effects.