The 1950 Malaria Conference in Equatorial Africa, held in Kampala, Uganda, has been remembered primarily for its decision to control malaria '...by modern methods as soon as feasible, whatever the original degree of endemicity, and without awaiting the outcome of further experiments.' This decision was far from conclusive and, indeed, reflects only one side of the argument which brought two groups of malariologists into direct opposition on the wisdom of malaria control in equatorial Africa, using modern methods such as DDT. Through an examination of the unpublished verbatim transcript of the Kampala Conference, we are able to document the 'furious debates' which took place at Kampala in 1950. We highlight, in particular, the adamant concerns expressed by some of the delegates that intervention in areas of high malaria transmission might lead to a loss of naturally acquired immunity which, in turn, could give rise to a resurgence of malaria, should the control strategies fail to be sustained. As we show, this concern had been expressed by a number of malariologists working in East Africa in the first half of the twentieth century, but it was only with the advent of DDT, as a residual insecticide, that the implications of wide-spread control, in the absence of any knowledge of the long-term consequences, became a serious possibility. While the Kampala Conference gave the 'go ahead' to control malaria in Africa without awaiting the outcome of 'further experiments', a number of participants insisted that a field trial should be set up to evaluate the impact of malaria on areas of high transmission both before and after spraying: to this end, a field trial in Pare-Taveta was carried out in 1954-59. In this paper we look at the Kampala Conference for its scientific debates and the Pare-Taveta Scheme for its field applications. In the final part of the paper, we address a number of questions raised at Kampala which have, once more, become contentious issues, following the recent successful trials of ITBNs. We believe that an understanding of the historical foundations of these issues should provide an important component of the new WHO campaign to Roll Back Malaria.