The purpose of this paper is to analyze some effects of export and food crop strategies on farm income and food self-sufficiency at the household level in the Eastern and upper Casamance regions of Senegal. The objectives of the government of Senegal include food self-sufficiency and export crop expansion through crop diversification. Over the last twenty years, extension programs have emphasized the introduction of cotton and maize. Although maize seems to have found its way easily in the existing farming system, the performance of cotton is less clear. After an initial rapid expansion, cotton acreage and production started to decline from the mid 70's. This raises questions about the lont-term suitability of cotton and emphasizes the need for additional research into what happens when new crops are introduced into the farming system, with possible implications for policy-making. Crop diversification as a strategy of development is dictated by the necessity to diversify national export earnings and reduce risk and uncertainty at the farm level. However, a policy which might appear sound at the macro level may be seen in a different light by the small farmer. There are two major questions about cash crops. First, are the returns in good years sufficient to offset the losses in bad years? Second even in good years, are the returns to cash crops high enough to enable the farmer to meet the food needs of his family? A personal observation is that the Senegalese small farmer asks himself these types of questions, particularly the second one. Whatever may be the tenor of the official crop diversification policy, priority is likely to be given to the food crops in his farming system. A central hypothesis of development theory is that farmers respond to prices and that farmers maximize income subject to certain constraints such as meeting family food needs. Therefore a policy of diversification which does not take into account farm level constraints, such as minimum food production, has little chance of success. In an agriculturally based economy, the macro and micro issues are so interrelated that it would be unwise to look at them separately. This paper undertakes a preliminary analysis of a particular crop diversification strategy - introduction of cotton - taking into account farm level constraints which might influence farmers' decision-making.