Desertification is an environmental issue that has major environmental and social dimensions, and which has been controversial in a number of respects. The recent UN Convention on Desertification and Drought places considerable emphasis on the social dimensions of the problem and the role local peoples and NGOs have to play in tackling it. When desertification first became regarded as a major issue in the 1970s, science was seen to have a major role in understanding and solving the problem, but in some circles has been regarded as failing to contribute usefully. This paper explores the nature of scientific contributions, why science may have been seen to fail to serve the needs of policy-makers, and why scientific findings may have been misinterpreted in broader circles dealing with the issue. It concludes by identifying areas where science has still a valuable role to play in an issue that is now perhaps regarded as more political and social than scientific. Keywords: desertification, societal issues, environmental issues, science-society interface.