Four hundred and eighteen native breed of sheep aged 6-18 months were reared in a private farm belongs to Wady El-Moallak, Ismailia governorate, Egypt, were examined for the presence of internal parasites and mange. Faecal samples and skin scrapings were collected from diseased animals for parasitological examination and serum for biochemical analysis. Faecal examination revealed that, 121 out of 418 sheep were naturally infested with gastrointestinal nematodes, indicating that the prevalence rate in the examined flock was 28.9%. The most prevalent nematodes recovered by larval cultural were Trichostrongylus spp. (33.9%). Haemonchus spp. (30.6%), Oestertagia spp. (18.2%) and Nematodiurus spp. (17.4%). While, skin scraping examination revealed that, 95 out of 418 sheep (22.7%) were naturally infested with psoroptic mange. Mixed infestation of Gastrointestinal nematodes and psoroptic mange Were recorded in 86 cases. A high rate (71.1%) of psoroptes ovis was found in gastrointestinal nematodes infested sheep, while it was low (3%) in gastrointestinal nematodes free animals. On the other side, serum biochemical analysis of minerals, total proteins and some vitamins in sera of infested animals revealed significant decrease in the levels of calcium, inorganic phosphorus. Copper, zine, total proteins and vitamins A and E. while significant increase in serum creatinine lev- el was noticed. Treatment of the infested animals with doramectin 1% (Dectomax) was found to be effective against gastrointestinal nematodes and psoroptic mange. In addition, supplementation of the diet with minerals and vitamins, beside spraying of the stables with diazinon assisted in recovery of the infested animals.The present observation declare the problem of naturally occurring of gastrointestinal nematodes- psoroptic mange interaction in sheep and it could I be concluded that, GIN infestation can enhance the establishment, survival and pathogenicity of concomitant psoroptic mange infestation.