Twenty Panicum maximum Jacq. genotypes from the International Center of Tropical Agriculture (CIAT) in Colombia were evaluated for adaptation in the humid region of Central Puerto Rico. In terms of the dry matter yield on the short- and long-day season and the total dry matter yield in both years (1988-89 and 1989-90), CIAT 6171, CIAT 6563 and CIAT 6533 were the most promising. The germination rate of these genotypes was similar to the general average of all the genotypes. Only CIAT 6533 did not flower during two cuts corresponding to the summer period.The soil covering ability of CIAT 6563 at the establishment was higher than that of the majority of the genotypes with the exception of CIAT 6171 and CIAT 6045. In terms of plant density (plants per square meter) and plant height at the establishment no significant differences (P=.05) were observed among the three genotypes.The three genotypes were consistently the highest in dry matter yield in both years under evaluation. The yield of CIAT 6171 and CIAT 6563 were more uniform in each of the seasons.