Chromosome numbers were determined for 63Anthuriumspecies. Thirty‐eight of these were newly determined. Generally the present work confirmed existing chromosome counts when these were available for comparison. The most common somatic chromosome number found was 30, but counts ranged from 2n = 20 to 90. In a few instances conflicting counts were obtained. B chromosomes were found frequently in Sect.Cardiolonchiumand varied in number from one to three. Four polyploid series were evident from all available counts: 20‐40, 24‐30‐48‐84, 28‐56 and 30‐60‐90‐ca 124. Most species were part of the polyploid complex based on 30. Although species were not observed with n = 5, 6 or 7, movement among the basic numbers was considered to have occurred at this level. The relationship among these basic numbers and n = 15 (x2) is still obscure.