The aim of this study was to identify bean genotypes with high yield potential when grown in soils of low fertility and under the pressure of foliar diseases. Diverse genotypes, known for its adaptation in soils of low fertility and/or resistance to other biotic and abiotic stresses were evaluated in the field during 1996 and 1997. In total, 562 genotypes, 251 bred and 311 landraces, were evaluated in two locations in Costa Rica: Fraijanes (1750 msnm; 15.3 °C; 3025 mm annual precipitation; 10º09’ North and 84°12’ West); and Alajuela (840 msnm, 23,1 °C; 1966 mm annual precipitation; 10°01’ North and 84° 16’ West). Plant stand was of 15 seeds per lineal m and plot size was variable due to seed availability; at planting inoculant of Rhizobium tropici was added directly onto the seed in the row (4 kg/ha). Bred line A 321, the control genotype UCR 55, A 483, G11640, G19696, G10843 and BAC50 displayed high yields in both locations. Genotypes that showed high yield in only one location were, in Alajuela: Guanajuato 132, Negro INIFAP, VAX 2 and MAR 3; in Fraijanes higher yielders were G13860, G92, MOC 112, Bayo Alteño, J 117; Negro 8025 and A 247. Outstanding landraces and bred lines from diverse geographical areas and genetic pools that displayed adaptation in soils of low fertility were identified in germplasm introduced from CIAT, México, Perú and Guatemala. It is emphasized the importance of evaluating native material and the exchange of germplasm among countries. Superior genotypes will be used for bean breeding in low input agriculture.