This document reports on a study of the chromosome numbers and nuclear types of 44 species from 20 genera of Cymbidioid orchids occurring in Brazil. Chromosome numbers ranged from 2n=12 in Psygmorchis pusilla to approximately 2n=168 in Oncidium aff. flexuosum. Interphase nuclear types varied widely. Chromosome numbers observed included 2n=54 for subtribe Eulophiinae, 2n=44, 46, 92 for subtribe Cyrtopodiinae, 2n=54, approximately 108 for subtribe Catasetinae, 2n=52, approximately 96 for subtribe Zygopetalinae, 2n=40, 80 for subtribe Lycast