In an infant with fatal disseminated histiocytosis-X, intractable diarrhea was the initial symptom and remained prominent during the further course of the disease. Intestinal biopsy revealed extensive histiocytic infiltration of the lamina propria. Although involvement of the gastrointestinal tract, mostly with diarrhea, is probably not unusual in generalized histiocytosis-X, this fact is rarely mentioned in the literature. Intractable diarrhea as a major symptom of this disease has not yet been described.