The methodology used included the collection of native maize varieties within the region, their evaluation in contrasting environments, and the development of populations. The selection squeme included the evaluation of progenies in farmers’ fields and recombination in the research station in order to avoid environmental changes. With such a system, we have improved the populations V-301, V-302, Barcena 71, V-304, V-305, Don Marshall and Chanin, all adapted to the Central plateau, and the populations of San Marceno, Guateian Xela, Compuesto Blanco, Toto Amarillo and Chivarreto, for the Occidental Plateau. The yield response to selection was positive, with gains up to 4, 3% per cycle and with a reduction in plant height and a better location of the ear in the plant. The yields for the improved varieties at the farmers’ fields, showed an average of 21 and 41% higher yields in comparison to the check for the central and the occidental plateau, respectively. Reports from the “Rural Socio-Economy” program indicated that the improved varieties were adopted by 50% of the farmers who participated in the technology transfer activities in the region.