Crop drying is the oldest method of preserving agricultural products. However, the developing countries experience considerable losses from the traditional practices of floor drying in the sun and subsequent storage. These post-harvest losses are discussed and followed by an analysis of the drying problem. This includes the disadvantages of natural drying, energy requirements, the effect on the environment of drying with fossil fuels and the limitations of both fossil fuel and electrically powered dryers. Solar drying is defined and a brief overview of solar insolation and sunshine hours in some developing countries is given. Over the years much effort has been devoted to make the natural drying processes more efficient by the introduction of solar technology. The potential for the use of solar dryers as an alternative to traditional sun drying methods in developing countries is outlined. The present status of the solar drying of agricultural products in those countries is assessed, leading to the final conclusions with recommendations for future action.