African governments are increasingly interested in understanding factors affecting the marketing of staple food grains by rural households which produce partially for home consumption. Food security depends not only on aggregate production, but also the distribution of production by income group, social class and geographical area. The availability of food to nonagricultural producers and those who produce insufficient amounts to satisfy their subsistence requirements is influenced by the interaction of variables affecting the allocation of production between sales and other disposals, consumption, and storage. Grain which is added to disposals limits household consumption as well as security provided by on-farm stocks. At the same time, if sold, it adds to income, affecting both consumption and security. Marketed surplus, in conjunction with gifts and in kind exchanges, comprises the disposable or marketable surplus component of output. Understanding the behavior of marketed surplus and the variables affecting it can be of major importance in the development of sound policies with respect to agricultural marketing and prices, imports and exports, national reserves and overall rural and national development objectives. At the present time, many African governments are involved in or contemplating involvement in the marketing of staple food products. International organizations and agencies are investing increasing amounts of money in food security and agricultural development assistance schemes, arguing for the urgency of meeting "basic needs". An understanding of the determinants of marketed surplus is an essential element of effective planning and program design. This paper is an outgrowth of an attempt to estimate simple supply and demand functions for staple food grains in a West African county.