Recent outbreaks of adenovirus (FAdV) infections in poultry flocks have been determined in many countries in Europe, Asia and Australia connected with economic consequences, and loses in poultry production. To better understand the evolution and transmission of FAdV viruses, de- tailed codon usage analysis was performed for 137 recently obtained FAdV strains. A high effec- tive number of codons, and an indication the presence of low codon usage were determined. The presence of mutations, and their influence on codon usage was confirmed by a correlation be- tween nucleotide compositions at the 3 rd codon positions, HVRs1-4, and ENCs. This presence indicate some influence of natural selection, and antigenic properties of examined FAdV strains.