Twenty six balady sheep were used to compare be efficacy of Nigella sativa with albendazole against nematodiasis. The blood and faecal samples were collected from all animals just before treatment and after 7, 14 and 2) days of treatment. Parasitological examination revealed the wesence of Trichostrongylus sp. (100%), Haewonchus sp. (75%), Ostertagia sp. (50%) and Oesophagostomum sp. (25%). The present results revealed that, anthelmintic efficacy was on [4th fay for albendazole and on 21" day for Nigella ativa. Nematode infestation leads to significant increase in serum activities of AST, ALT and ALP, in addition to significant decreases in total protein and albumin. However, the parasitism resulted in significant decreases in scrum levels of ~u, Fe, Zn, Ca and P as well as significant decreases 1n RBCs, Hb and PCV values associated with significant increases in TLC, neutrophils, eosinophils and monocytes count with significant decrease in lymphocytic count. These parameters began to corrected toward normality on 7^th day post treatment with albendazole or nigella sativa. The data declared a good efficacy of albendazole and nigella sativa respectively where the derangements were corrected on the 7^th day. The use of nigella sativa in correct dose as anthelmintic drug may reduce egg counts and can overcome parasitic infestation in sheep.