||This paper reviews trends in rainfed maize production in Mexico over the past several decades, and the experience of lNIFAP/ CIMMYT/ CIRAD on-farm research (OFR) in Mexico's lowland tropics, to evaluate the prospects for increased maize production in rainfed regions. National production data show that rainfed maize area has remained stable since 1960 and has even decreased in the last decade; average yields have been leveling off since 1980 after strong gains in the 1970s. However, the rate of growth in maize yields necessary to meet the demand expected in the year 2000 (1.7% per year) far surpasses yield growth rates registered since 1980. Futhermore, prices of inputs and credit used for maize production are likely to be less favorable in the future than they were in the past, meaning that the area planted to maize and maize yields are likely to decline unless new technologies become available. Results of six years of OFR in Mexico's lowland tropics indicate that it is possible to generate economically viable technologies that would enable farmers to increase yields of rainfed maize. However, doing so on a wide scale implies a reorganization of the research agenda, an increased emphasis on farmer participatory research, and additional investment in agricultural research.