Mesenteric inflammatory pseudotumor in infants is a rare disease entity. To our knowledge, only scattered reports of this condition have appeared in the literature in English and there is no previously published report in Korean. We describe a case of mesenteric inflammatory pseudotumor in an infant. Ultrasonography revealed an inhomogeneous solid mass with hypervascularity, contrast-enhanced CT showed a large, inhomogeneous mass with ill defined hypo and hyperattenuated areas.