A cross sectional study was conducted from January 2015 to May 2015 to characterizernthe pathological changes and to determine seroprevalence of IBD and its associated riskrnfactors in chickens in and around Bahir Dar. The clinical signs observed in IBD infectedrnchickens were whitish diarrhea mixed with blood, ruffled feather, and massive deathrnwithin short period. The necropsy findings were petichial hemorrhage in bursa ofrnfabricius, kidney, thymus, spleen, thigh and pectoral muscles. Bursa of fabricius becamernedematous in serosa and mucosal part, whitish-creamy and atrophied as the course of therndisease progressed. Kidney became pale and ureter was turgid with urate in a numbers ofrncases. The histopathological changes in this study revealed that edema of bursa ofrnfabricius, formation of cystic follicles, depletion of lymphocytes, fibrosis and follicularrnarchitecture lost. Severe, moderate and mild lesion score were observed in bursa ofrnfabricius. Infiltrations of heterophils were noted both in lymphoid and non lymphoidrntissues. Depletion of lymphoid cell in germinal center of spleen and total depletion ofrnlymphoid cells were encountered in thymus gland. The kidney tubules were filled byrnexudates and necrotized cuboidal cells. Sera collected from a total of 320 chickens werernsubjected to IELISA test and disclosed an overall prevalence of 51.56% (CI: 45.95 â€“rn57.14) in study area. The seroprevalence of IBD among chickens showed a statisticallyrnsignificant difference (P