Parasitic infections are highly prevalent in the general population. A relation between a parasitic infection and absorption of minerals is not an easy task. Serum levels of copper, zinc and magnesium were prospectively measured in 64 children with intestinal parasitic infection. Thirty-nine children with Enterobius vermicularis were treated with pyrantel pamoate and 25 children with Giardia lamblia with tinidazole and metronidazole. Three months after treatment, significant differences in serum copper, zinc and magnesium were seen in patients with E. vermicularis infection, and in serum magnesium levels in patients with G. lamblia. Although the pathogenic mechanism is not clear, these findings could reflect a deficiency related to malabsorption due to mucous affection. Early detection and treatment of intestinal parasitosis could avoid these serum mineral deficiencies.