This manual presents a set of procedures for doing an economic analysis of on-farm agronomic experiments wich will help in selecting treatments for furter experimentation and for developing farmer recommendations. The following points are discussed: importance of reviewing the objectives of the experiment; the experimental design and management; how to calculate total costs that vary, average yields, adjusted yield, gross field benefits, and net benefits; how to develop a partial budget; the importance of dominance analysis, marginal analysis, minimum returns analysis, and sensitivity analysis; and how to draw and report appropriate