Broiler chickens in Egypt represent the main source of animal protein. Unfortunately, they usually are hit by many disease problems. Respiratory and renal affections are investigated in forty four broiler chicken flocks aged (19-54) days and suffering from respiratory and renal distress during 2014-2015 in three large Governorates; Sharkia, Dakahlia and Gharbia Variable mortality rates (0.5-30%) were recorded. On necropsy, tracheitis, bronchitis and congestion of lungs were recorded in all examined flocks. Caseated plugs at tracheal bifurcation 28/44, fibrinous pericarditis, perihepatitis and air sacculitis 19/44 were also observed. Nepherosisnephritis 22/44, and General congestion with hemorrhage on proventriculus 9/44 and cecal tonsil 4/44 were seen among affected birds. Chicken embryo inoculation for IBV isolation revealed reduction in embryo size was recorded in 20%, death within 72h in 54.5% while 11% of flocks required successive blind passage to show reduction in embryo size up to 2cm compared to 5cm in negative control. Thirty three out of forty four harvested allantoic fluids were positive with Heamagglutination test (75%). The reverse transcriptase polymerase chain reaction (RT-PCR) was carried out on both original tissues and allantoic fluids using specific primers for S1 gene. Nine positive infectious bronchitis viruses (IBVs) (20%) were detected in original samples compared with only 2 (4.5%) in allantoic fluids of the same samples. It could be concluded that the IB virus infection did not exceed 20% of the causative agents in disease condition in question and usually in mixed infection. In turn the use of variant vaccines did not solve the problem but exacerbated the emergence of new IB viruses. There were clear evidence that HA virus did the main role in such disease problems. The direct RT-PCR could be reliable tool for appropriate IBV diagnosis to estimate the real situation in chicken diseases.