The article deals with rare disease in children — autoimmune enteropathy. The basis of the disease is persistent protein-losing diarrhea, associated with production of autoantibodies, — a sign of an active autoimmune T-cell inflammation. Histomorphologically, the disease is characterized by atrophy of the villi and massive mononuclear infiltration of lamina propria of the small intestine. The article presents a review of literature and our own observations of autoimmune enteropathy in infant. Disease in a child ended fatally, as initially it had a poor prognosis: early onset, persistent diarrhea, renal involvement (nephrotic syndrome), associated defeat of small and large intestines.