Among the most innovative – albeit least well known – features of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) regime is the use of trade sanctions for noncompliance with the treaty. Though not foreseen at all in the original text of the Convention, a unique system of ‘collective retorsion’ was gradually developed through a series of resolutions by the Conference of the Parties, by way of trade embargoes – that is, multilateral recommendations to suspend trade in CITES-listed specimens with the country concerned. Since 1985, this scheme – now codified in the 2007 Guidelines on Compliance with the Convention – has been enforced against at least 43 recalcitrant States (parties and non-parties). This article reviews the historical evolution of the CITES sanction scheme in practice over the past three decades, and its effectiveness in achieving compliance. The legality and legitimacy of the scheme is assessed in light of the Convention, other relevant international instruments and general rules of international law.