A reverse transcriptase-polymerase chain reaction (RT-PCR) technique was used to detect infectious bronchitis virus (IBV) in the commercial broiler flocks in Syria. 50 tissue samples were taken from tracheal tissue, trachea and kidney of the broilers suspected of infectious bronchitis (IB) from different governorates of Syria i.e. Latakia, Tartous, Hama and Damascus countryside. RNA was extracted directly from the tissue samples and then RNA was converted to cDNA by RT-PCR technology; PCR reaction and Nested PCR interaction were carried out sequentially. The primers used in the RT-PCR reaction were selected from the S1 gene (spike), where mutations of the virus genome were concentrated in this region (the hypervariable region). Some positive samples (10) were injected at an age of 9-11 days old SPFEE-specific pathogen free embryonated eggs according to the methods adopted in virology. This research was carried out at the laboratories of Latakia Research Center, General Commission for Scientific Agricultural Research GCSAR, in cooperation with the PCR laboratory at the Faculty of Veterinary Medicine in Hama. The results showed the existence of 37 positive case for RT-PCR (74%), and the infectious embryos showed clear and characteristic anatomical lesions of the infectious bronchitis virus after 5-6 days post injection, delayed and undeveloped fetal (dwarfism), fingertip entanglement and hemorrhage compared with the negative control. The results also showed the sensitivity and speed of the RT-PCR test in the detection of the IBV virus.