With increased private investment in crop breeding research in the developed world, intellectual property rights have gained importance in seed sector. Trade Related Aspects of Intellectual Property Rights (TRIPS)-plus provisions included in recent free trade agreements between the developed and developing countries show a tendency of the developed world to impose their high standards for protection of plant intellectual property on the developing world. While stronger intellectual property rights can increase international exchange in seed, market power effect can lead to a reduction in exports of seed to foreign markets. This article estimates the impact of intellectual property rights on U.S. seed exports. The estimation is performed at a crop level using Heckman selection model. The results reveal that the impact of intellectual property rights varies across different types of crops—open-pollinated, genetically modified, and hybrid crops. While TRIPS provisions are important to facilitate transfer of genetically modified crops, they play a minor role for open-pollinated and hybrid crops. The results also show that plant breeders’ rights envisioned by the UPOV system can be important to promote seed exchange when proper mechanisms are put in place to enforce these rights.