Thu-Lang Tran Wasescha is currently Counsellor in the Intellectual Property Division of the World Trade Organization and serves as Secretary to the Special Session of the Council for TRIPS (Doha Round's ad hoc body dealing with the negotiation of the establishment of a multilateral system of notification and registration of geographical indications for wines and spirits).

From 1986 to 2000, Thu-Lang Tran Wasescha was Senior Legal Adviser and Director of the Department of International Affairs of the Swiss Intellectual Property Institute, Ministry of Justice, where she dealt with the international aspects of intellectual property, including technical cooperation. She represented Switzerland in IP/TRIPS negotiations and discussions in various fora, e.g. GATT/WTO, WIPO, WHO, FAO, CBD and EFTA. She was deputy head of the Swiss TRIPS negotiating team in the Uruguay Round and responsible for the implementation of the TRIPS provisions in the Swiss domestic law. From 1976 to 1986, she was Principal Legal Officer in the Industrial Property Division of the World Intellectual Property Organization (WIPO). Prior to this, she worked as a junior legal assistant in a Swiss trademark agent office specialized in the filing of trademark applications and of marketing authorization applications in the area of pharmaceuticals.