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 during 2014-2015 in three large Governorates; Sharkia, Dakahlia and Gharbia. The birds age ranged from 19-54days and suffured from general signs of illness, respiratory troubles with Whitish and greenish diarrhea. Mortality rates ranged from (0.5-30%). On necropsy, tracheitis, bronchitis and congestion of lungs were recorded in all flocks. Caseated plugs at tracheal bifurcation (29/44), fibrinous pericarditis, perihepatitis and air sacculitis(19/44) were also observed. Nepherosis-nephritis (22/44) and General congestion with hemorrhage on proventriculus (n=9) and cecal tonsil (n=4) were seen among affected birds. Chicken embryo inoculation with respiratory and renal tissue suspension revealed reduction in embryo size (n=9), death within 72hrs (n=24) while 5 flocks required successive blind passage to show reduction in embryo size up to 2cm compared to 5cm in negative control. 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 virus (IBV) were detected in original samples compared with only 2 in allantoic fluids of the same samples. It could be concluded that IBV is responsible on 20% of respiratory and renal troubles in broilers under investigation. The direct RT-PCR could be reliable tool for appropriate IBV diagnosis in chickens.