This study investigates the prevalence of gastrointestinal nematodes in ruminants in Ismailia, Port-said and Damietta cities, during a period from October 2016 to September 2017. A total of 130 fecal samples were collected from sporadic cases and 60 abomasal samples and 36 small intestinal samples were collected from slaughtered animals in abattoirs to detect the adult nematode parasites. The results indicated that sheep was infected with 5 species of nematodes 3 in abomasum and 2 types in small intestine. The prevalence of the infection were 26.15%, 30% and 11.11%   in faecal , abomasal. and small intestine samples respectively. The highest prevalence of the nematodes was in young animals (71.42% in ovine sp., 14.28% in bovine sp. and 0.0% in caprine sp). Higher prevalence was in male sheep 60% than ewe 30%. Damietta was the highest in prevalence (47.6%) then in Ismailia (29.16%) and 0.0% in Port-said. The most prevalent species of nematodes in abomasum was Haemonchus contortus (26.67%), Ostertagia sp. (10%) and Trichostrongylus axei (3.33%). In small intestine, were Cooperia sp. (11.11%) and Nematodirus sp.(5.56%). Faecal egg count reduction test was carried out on Ivomec super & Albendazole to demonstrate the efficacy of anthelmintics,  and proved the Ivomec was more potent than Albendazole in treatment of GINs.