Background and Aims: Infectious bronchitis virus (IBV) is the causative agent of avian infectious bronchitis, which is characterized by respiratory, reproductive, and renal signs. IBV is a highly variable virus with a large number of genotypes. S1 gene sequencing has been used for molecular epidemiological studies and genotypic characterization of IBV. To better understand the molecular epidemiology of IBV in Iran, we sequenced the S1 gene of IBV field isolates, a total of 40 tracheal and kidney tissue specimens from different commercial broiler flocks in the East of Iran were collected from 2015. Materials and Methods: 15 IBV-positive samples were selected from among the total and were further characterized by sequencing the spike glycoprotein gene. The isolates were confirmed by real-time polymerase chain reaction (PCR) and characterized by sequencing the spike glycoprotein gene. Results: Three genotypes were detected. The percentage of Variant 2 (IS/1494 like), 793/B, and QX genotypes was 66.7%, 26.7%, and 6.6% respectively. We reported the QX as the first time and Variant2 was the dominant genotype in this area. Conclusion: It is an updated and comprehensive study of genotyping of IBV and completes IBV puzzle in the East of Iran.