This paper provides an overview of work on trade and environment in the OECD since the creation, in 1991, of the Joint Session of Trade and Environment Experts, later re-named Joint Working Party on Trade and Environment, and summarises the main conclusions and policy recommendations arising from that work. It describes work done in three key periods: • From 1991 to 1995, starting with the establishment of the Joint Session of Trade and Environment Experts, up to the conclusion of the Uruguay Round and the creation of the World Trade Organisation and its Committee on Trade and Environment. • From 1995 to 2001, spanning discussions up to the adoption of the Doha Development Agenda (DDA), in which Ministers mandated negotiations on a range of topics related to trade and environment. • From 2001 to 2008, focussing on analytical work to support discussions under negotiation in the DDA at the WTO and exploring emerging issues outside of the DDA.