 Illegal, unreported and unregulated or IUU fishing drains our oceans, seas, lakes and rivers of precious resources. It is one of the greatest threats to fisheries sustainability. It occurs in all types of fishing and impacts fish stocks, the environment and the livelihoods of communities that depend on fishing. IUU fishing takes advantage of corrupt administrations and weak management, especially in countries that lack the capacity and resources for the effective monitoring, control and surveillance of fishing activities. IUU fishing is not just about breaking fishing regulations. It also includes not reporting or misreporting fishing activities and the catch and conducting unregulated fishing activities which often contribute to over-exploitation of fisheries resources and impact the environment. The damage caused by IUU fishing is serious, but there are ways to eliminate it. The FAO agreement on port state measures, known as the PSMA, has been enforced since 2016. Its objective is to block foreign vessels engaging in IUU fishing from using ports to offload their catches and other services or even denying entry. The agreement provides a powerful mechanism for governments committed to combating IUU fishing. The PSMA permits states to have robust provisions in national legislation on port state measures to keep fish derived from IUU fishing away from our markets. The PSMA is the world's first ever binding international agreement specifically targeting IUU fishing. To support its effectiveness, FAO provides technical assistance to developing states to strengthen their legal frameworks, institutional capacity and operational procedures. More than 40 states have received or are receiving FAO support. The number of parties to the agreement continues to increase, with more than half of the world's port states taking it up. But this is not enough. A concerted action is essential on a global scale. The PSMA will become more effective as more states become party to it. Each state that implements the agreement is one less door available to IU fishers. States must ensure that their ports become a solution to combating IU fishing and not part of the problem. Five years on from the coming into force of the agreement, a third of the parties have already denied entry or use of port to vessels believed to have engaged in IU fishing. The PSMA plays a key role in achieving sustainable fishing and FAO strongly encourages all members to become a party to the agreement and strengthen regional and global cooperation to combat IU fishing. Sustainable fishing starts with us.