Avian metapneumovirus causes acute and highly contagious upper respiratory tract infections in chickens and turkeys. Avian metapneumovirus plays an important role in respiratory diseases; it may be involved in multifactorial disease. The aim of this study was the detection and molecular characterization of avian metapneumovirus from commercial chicken flocks in Iran. Clinical samples from 50 commercial chicken flocks with respiratory signs such as swollen infraorbital sinuses, nasal discharges, coughing, tracheal rales and foamy conjunctivitis were collected and brought to the Razi vaccine and serum research Institute for RT-PCR. Samples included the choenal cleft, trachea and turbinate's swabs. The G genes of Positive samples were sequenced. Of the 50 chicken flocks, 8 flocks were positive by RT-PCR (16%). Partial sequence analysis of the G gene confirmed that the positive samples belonged to subtype B. Phylogenetic tree demonstrated that Iranian strains formed one group apart from subtype B vaccine strain used in Iran. Comparison of nucleotide sequences of the Ggene of the Iranian aMPV samples with subtype B isolates from other countries revealed 95.2% to 97.4% identity. Nucleotide sequences showed 96.9 to 97.9% identities among the Iranian samples and 95.5 % identity with the subtype B vaccine strains used in Iran. (C) 2015 IASE Publisher All rights reserved.