[1] Lee began his career as a veterinary surgeon and worked as a research and development officer in the Singapore Government's Primary Production Department between 1972 and 1981.
Lee subsequently worked at the US Feed Grains Council as Assistant Regional Director and later Senior Project Manager for Primary Industries Enterprise between 1981 and 1984.
Lee resigned from the Cabinet in 2009 but remained as a Member of Parliament on the backbenches until his retirement from politics in 2011.
[citation needed] Lee was appointed Chairman of the Board of Keppel Corporation in 2009, after resigning from the Cabinet, where he served until 2021.
[3][4][5] He also served as Chairman of Singapore Press Holdings between 2011 and 2022, before he was succeeded by Christopher Lim.