This paper analyzes how the Cartagena Protocol on Biosafety, a global regime governing trade in genetically modified organisms (GMOs), is influencing agricultural biotechnology policy choices in developing countries/emerging economies. Through empirical analysis of Mexico, China and South Africa, we examine whether discursive and/or institutional change has followed the negotiation and implementation of the Cartagena Protocol in these countries. We find that, although trade and market competitiveness concerns are driving biotechnology policy choices in all three cases, a precautionary biosafety discourse has gained greater legitimacy as a result of the Cartagena Protocol, empowering those domestically who voice such concerns. Related to that, debates and/or decision- making processes in this controversial area have become more inclusive in all three countries-an important influence of the Cartagena Protocol. We also find persisting regulatory diversity rather than harmonization of biosafety regulatory frameworks in our three countries, with international trade linkages and domestic politics playing an important mediating role in determining Protocol influence.