This paper introduces the concept of 'working utopias' (WUs) and explores their relation to social movements. WUs are used in a variety of ways by social movements, it is argued, and they play a central role in the reproduction and advancement of movements. They reproduce the movement habitus and illusio, extend and reproduce networks, generate new forms of knowledge and practice, and serve, to some extent at least, as 'proof' of the validity of movement claims. Two utopias from within radical mental health movements are focused upon in the paper: the Kingsley Hall therapeutic community and the 'Trieste experiment'. The significance of these working utopias is explored by way of interviews with movement activists who have been involved with them in various ways. [ABSTRACT FROM AUTHOR]