Background: Avian Reovirus (ARV) is involved in many pathologic syndromes of chicken including the both major syndromes, Viral Arthritis (VA) and Runting Stunting Syndrome (RSS), which have great negative impacts on the poultry industry. Although ARV was reported in Egypt since 1984 but only few studies figured out the implication of ARV only in the uneven growth of some Egyptian chicken flocks. Aim: Clinical and molecular investigation of avian reovirus infection in broiler chickens with availability of Vertical Transmission Methods: Herein, 18 chickens derived from 4 broiler flocks within Sharkia Province, Egypt suffering from different degrees of lameness and/or stunting were clinically and molecularly examined for the presence of ARV. Results: By clinical examination, one third (6/18) of examined chickens showed bilateral arthritis with tendons included microscopic changes consistent with the typical ARV infection. Additionally, eight chickens (8/18) showed stunting and another one chicken (1/18) showed poor feathering while the last three chickens (3/18) appeared diarrheic. All clinically affected chickens showed varied postmortem lesions that almost associated with ARV infections. Further molecular detection of ARV within the 18 clinically affected samples (n=18) by RT-PCR using a specific primer set targeting a conserved sequence within ARV- sigma C protein revealed 7/18 positive samples. All positive samples (7/18) were successfully isolated on specific pathogen free embryonated chicken eggs (SPF-ECE). Additional RT-PCR testing and re-isolation of ARV from ECEs of a breeder flock of a history of uneven growth and/or arthritis revealed ARV infection in six (6/60) examined ECEs. Conclusion: These results indicated the incrimination of ARV infection in some arthritis infections beside the low food conversion rate of chickens within Sharkia Province, Egypt. Moreover, the obtained data highlight the importance of vertical transmission in the field spread of ARV infections.