Infectious bursal disease (IBD) is a main health problem causing considerable economic losses in poultry flocks in Egypt. Throughout 2018-2019, bursae samples were assembled from different chicken's farms localized in four Egyptian governorates (Giza, Bani-Suif, Fayoum and Qalubia). The samples collected from farms recorded history of Infectious Bursal Disease (IBD) signs such as: sudden mortalities; depression; diarrhea; and hemorrhages on bursal tissues, leg and breast muscles. For virus isolation, the collected samples were cultivated in Specific Pathogen Free Embryonated Chickens Eggs (SPF–ECEs) via Chorio-Allantoic-Membrane (CAM).To confirm obtained data of virus isolation, both Agar gel precipitation test (AGPT) and  the Reverse Transcription-Polymerase Chain Reaction (RT-PCR) were applied. In AGPT results, the four IBDV isolates gave positive reaction by reference IBDV antisera. RT-PCR was done for amplification of VP2 gene of IBDV isolates. The four viral isolates introduced specific band at size of  620 bp. Pathogenicity test for isolates of IBDV represented that the IBDV isolate no. 1, 2, 4 belong to classical virulent IBDV (cvIBDV) serotype, while IBDV isolate no. 3 belong to very virulent IBDV (vvIBDV) serotype that caused high mortality rates than cvIBDV isolates. The presented results emphasize the determined screened of the IBD field state, as well as apply of supplementary studies to found successful policies to obstruct the viral infection in chicken flocks in Egypt.