Examination of 270 deer (of both sexes and aged from 3 months to 7 years old) belonging to different Egyptian zoo gardens between January and December 1996 revealed the presence of Trichuris, Trichostrongylus, Nematodirus, Strongyloid and Dectyocoulus eggs in 109 out of 270 deer. The highest rate of infestation occurred in winter (59.385) and on the contrary, summer season showed a low rate of infestation (33.59%). Infestation with internal parasites resulted in reduction in total erythrocytic count, haemoglobin concentration and packed cell volume, in addition to higher MCV and lower MCHC indicating macrocytic hypochromic anaemia. Moreover, leucocytosis, neutrophilia and eosinophilia, while lymphopenia were observed. Marked reducation in total serum protein, albumin, calcium, sodium, potassium, chlorides, and iron were noted in infested deer, while blood urea concentraton and the activity of serum enzyme alkaline phosphatase appeared to be elevated in infested deer versus those apparently healthy ones. An improved towards the normal level in previously mentioned parameters was observed after treatment with Albendazole and Fenbendazole drugs.