Chromosome numbers are reported for 127 germplasm accessions of Paspalum notatum maintained by EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária) in two research centers in Brazil. Most accessions were collected in their natural habitats in Southern Brazil. Tetraploidy (2n = 40 chromosomes) was predominant (91% of the accessions studied), confirming previous reports for the species. Eleven accessions with 2n = 20 chromosomes, although collected in the wild, are possibly derived from 'Pensacola' bahiagrass, commonly cultivated in the area since its introduction from the United States in the 60's, for the establishment of permanent pastures.