The Pioneer Health Centre, based in South London before and after the Second World War, remains a source of interest for advocates of a positive approach to health promotion in contrast with the treatment of those already ill. Its closure in 1950 for lack of funds has been blamed on the then recently established National Health Service, but this article argues that such an explanation is over-simplified and ignores a number of other factors. The Centre had struggled financially during the 1930s and tried to gain support from the Medical Research Council. The Council appeared interested in the Centre before the war, but was less sympathetic in the 1940s. Around the time of its closure and afterwards, the Centre was also involved in negotiations with London County Council; these failed because the Centre’s directors would not accept the changes which the Council would have needed to make. Unpublished documents reveal that the Centre’s directors were uncompromising and that their approach to the situation antagonised their colleagues. Changes in medical science also worked against the Centre. The success of sulphonamide drugs appeared to render preventive medicine less significant, while the development of statistical techniques cast doubt on the Centre’s experimental methods. The Centre was at the heart of the nascent organic farming movement, which opposed the rapid growth of chemical cultivation. But what might be termed ‘chemical triumphalism’ was on the march in both medicine and agriculture, and the Centre was out of tune with the mood of the times.