The literature pertaining to the prevalence of avian hematozoa in the Neotropics, together with unpublished records from the files of the International Reference Centre for Avian Haematozoa, was examined with respect to the distribution of parasite genera by host family and region. The blood parasites of 35,555 birds of 955 spp. (80 families) occurring in the Neotropics formed the basis for the comparisons. Only 3743 (10.5%) individuals harbored 1 or more species of hematozoa. Haemoproteus was the most commonly observed form exhibiting a 7.4% prevalence, followed by Plasmodium (1.9%), microfilaria (1.2%), Trypanosoma (0.6%) and Leucocytozoon (0.2%). Hematozoan prevalence varied markedly from region to region and among families. In comparison with a similar view of Nearctic avian hematozoan distribution, the Neotropics demonstrated a much lower prevalence and a near absence of Leucocytozoon.