This article uses household survey data from Bamako, Mali, to address three questions, important in the policy debate concerning the determinants of the substitution from coarse grains to rice in West African diets, and policy options. The questions are: (1) what are the relative costs of rice and coarse grain-based dishes, with and without complementary sauce costs? (2) What are the shares in total cost of individual processing and preparation stages? (3) Are pre-processed coarse grains (e.g. dehulled grain or flour) cheaper to consume than coarse grains processed in the household? Contrary to prevailing opinion, the paper shows that despite higher processing costs, coarse grain-based dishes are cheaper than rice-based dishes. The main contributory factors to the higher cost of rice-based dishes are sauce cost, cereal cost and preparation (cooking and sauce preparation) time. The result holds true over a wide range of rice and coarse grain prices, and opportunity costs of women's time, suggesting that the finding applies more generally to the urban Sahel and not just Bamako. Moreover, coarse grain-based dishes need not take longer to process and prepare than rice-based dishes if the dehulling step is mechanized. However, pre-processed coarse grains are not competitive with household processing given present technology and opportunity costs of women's time. Nor will coarse grains be able to retain the extent of their cost advantage over rice as incomes and labor opportunity costs rise without improvements in the efficiency of processing services.