The study was carried out to know the effect of black seeds on chicken experimentally infected with Gumboro virus. A total of 130 chicks were used. Experimental birds were divided into 4 groups. The first group of 20 birds was treated with black seed, second group consist of 30 birds was kept as non-infected non-treated control, third group of 40 birds was infected with IBDV, while fourth group of 40 birds represented SBDV infected and black seed treated birds. Infected chicks showed decreased body weight, bursal and thymus indices with 10% mortality. Infected birds treated with black seeds showed an increase in body weight with 2.5% mortality. Gumboro infection induced biochemical alterations in blood and tissues of infected birds. It decreased total protein, γ globulin, hepatic and bursal ascorbic acid. While it increased α1 globulin, uric acid, GOT, GPT, bursal and renal MDA. With no alterations in creatinine, GSH, renal ascorbic and hepatic MDA. Infected birds treated with black seeds had decreased total protein and albumin but immunity is raised as shown by increasing γ globulin and antibody titers which detected by HI and ELISA testes for NewCastle and Gumboro viruses. Treated Infected birds with black seeds succeed to restore uric acid, renal MDA and partially GPT but failed to restore GOT and bursal MDA. In conclusion, black seeds showed its cytoprotective, antioxidant and antiviral effect through its non specific immunostimulant role against Gumboro virus challenged birds.