The chicken genome comprises 78 chromosomes which include several macrochromosomes and many microchromosomes. Very little information is currently available concerning chicken centromere structure and function and it is unclear if the two types of chromosomes share a common centromere mechanism or whether this mechanism resembles those in other species. Immunofluorescence studies using antibodies to mammalian constitutive centromere proteins CENP-A, CENP-B, and CENP-C and the passenger proteins CENP-E, and CENP-F revealed the presence of each of these proteins at the centromeres of both macro- and microchromsomes. CENP-A, CENP-B, and CENP-E levels showed variability between metaphase centromeres while CENP-C and CENP-F levels were relatively constant. These results suggest a common centromere mechanism for both types of chromosomes as well as indicating a high degree of conservation of individual proteins between widely divergent vertebrate classes and an overall conservation of centromere function throughout vertebrate evolution.