With economic globalization, there is an increasing rate of cross border crime. Governments realize it is inefficient or not sufficient to control crimes within their territory by simply using their internal powers. Therefore, some conventions were drafted aiming at standardizing substantial crimes and also at strengthening procedural cooperation among countries in criminal matters. Legal assistance for confiscation of proceeds of crime is one aspect that has been addressed in recent years by many conventions. The purpose of legal assistance is to effectively trace and confiscate assets, especially in matters such as money laundering and corruption. To effectively prevent and control these crimes and to find and confiscate the proceeds, it is necessary to have legal assistance among different countries so as to ensure cooperation and a degree of harmonization on asset confiscation. When the process happens to be successfully concluded, the issue of asset sharing among the jurisdictions involved then arises. The substantive international rules on asset confiscation will be presented and discussed in the thesis, based on the important global convention, the 2003 United Nations against Corruption. A small reference will also be made to civil confiscation, which is not required by international law and is an optional approach in the fight against crimes. The thesis shall address the methods of cooperation. How does legal assistance work? Are there obstacles to cooperate? Key Words: international legal assistance, seizure, confiscation, proceeds of crime