The experiment was designed to study the immunological and biochemical effects of Nigella sativa (NS) and Ultra-Natural plus (UP) on turkey poults vaccinated against Newcastle disease (ND) and turkey Rhinotracheitis (TRT) virus vaccines. The results indicated the immunostimulant effect of both NS and UP but the former was more superior. Results at 4 weeks of age proved that Nigella Sativa gives ND HIGM titer, Optical density for TRT, Total serum protein and gamma globulin were 8.6, 0.943, 2.88 and 1.02 versus of 7.4, 0.922, 2.55 and 0.85 in Ultra-Natural plus; respectively. Nigella Sativa challenged groups using NDV and TRTv showed 93.34% and 100% ; respectively while Ultra-Natural plus challenged groups showed 86.67% and 93.34%; respectively.