This study was designed to evaluate the immune responses in children infected with E. histolytica after treatment with metronidazole. Immunological evaluation was performed by measurement of secreted cytokines (interleukin, IL-10-tumor necrosis factor-α in blood of children, on the other hand E. histolytica cyst output in children stool was measured. The present investigation is directed to study the therapeutic effect of different doses of metronidazole a treatment known for controlling of E. histolyticainfection in children. The children infected with E. histolytica were divided into three group according to the dose of metronidazole(Flagyl syrup). The 1st, second and third group were treated with 30, 25 and 15 mg /kg per day for 7 days, in 3 doses respectively. The results of the present study revealed a significant reduction in cyst count in stool of children treated by metronidazole at dose of 30 mg /kg in comparison with control un treated. The data also revealed that serum IL-10 and TNF-alpha were significantly increased as an immunological response for children treated with metronidazole at dose of 30 mg/kg body weight in comparison with children of dose 15 mg and untreated control group. Also the NO level revealed significant decrease in children at dose 30 mg / kg in comparison with 25 and 15 mg/kg group.