In 1965, Widgery met Allen Ginsberg, then visited Watts, where he encountered the civil rights movement, followed by Cuba. On return to Britain, he studied medicine at the Royal Free Hospital Medical School before writing for the New Statesman and Oz magazines, becoming co-editor of Oz during 1971.
Widgery joined the International Socialists in 1967, remaining in the group as it became the Socialist Workers Party. In 1972 he began working at Bethnal Green Hospital, and later in the decade he published his first book, The Left in Britain, 1956–68.
His books include The Chatto Book of Dissent (1991), an anthology of dissident writings co-edited with Michael Rosen, Some Lives!: A GP's East End (1991), the story of his experience as a doctor in London's East End, The National Health: A Radical Perspective, and Beating Time (1986), an account of the Rock Against Racism movement of the late 1970s.
When Widgery died, aged 45, excess alcohol, barbiturates and pethidine were found in his bloodstream, but it is not known whether this was an accidental or intentional overdose. One obituary described Widgery as "a radical humanist intellectual on permanent loan to revolutionary socialism."
- Widgery, D. (1976), The Left in Britain, 1956-68 (Peregrine Books)
- Widgery, D. (ed) (1980), The Book of the Year: September 1979 to September 1980 (Inklinks)
- Widgery, D., The National Health: A Radical Perspective
- Widgery, D. (1986), Beating Time
- Widgery, D. (1989), Preserving Disorder (Essays on Society & Culture) (Pluto Press)
- Widgery, D. and Rosen, M (eds) (1991), The Chatto Book of Dissent (Chatto)
- Widgery, D. and Sheldon, S. (1991), Some Lives!: A GP's East End, London: Sinclair Stevenson.
- Widgery, D. (1991), Marketa Luskacova: Photographs of Spitalfields (Whitechapel Art Gallery)
- "Widgery, David John Turner", Oxford Dictionary of National Biography
- "David Widgery". National Portrait Gallery. Retrieved 9 March 2009.
- Taylor, L. & Taylor, I. (eds) (1972), Politics and Deviance, Harmondsworth: Penguin, p. 213.
- James Le Fanu, "Confronting an Ill Society", J R Soc Med., 2005 July; 98(7): 332–333.
- Bob Light, "The Human Face of Revolution", Socialist Review, November 1992.
- David Widgery Internet Archive
- 'The Poetics of Propaganda' by Dave Renton
-  obituary by Michael Rosen
- obituary in New Left Review, I/196 (1992) by Paul Foot
- Obituary in Socialist Worker by Chris Harman
- David Widgery: Against Oblivion by David Hayes