In a series of 320 patients with lymphoid neoplasms treated with polychemotherapy, three patients with non-Hodgkin's lymphoma and one with myeloma were diagnosed as having neutropenic enterocolitis (NEC). All patients were adult, all had received multiple chemotherapeutic drugs and, during neutropenia, they had clinically presented with fever and abdominal pain, generally in the right lower quadrant. The diagnosis was clinical in all cases, and the imaging techniques provided only the suspicion of retro-cecal abscess in one of them. Two patients were operated on because of the development of features of peritoneal involvement, another because of septic shock and another because of retro-cecal abscess. Surgery and pathological study confirmed the diagnosis. The fundamental findings were ileocecal wall edema, mucosa ulceration, local necrosis, hemorrhage and thrombosis, and clusters of bacterial colonies without evidence of granulocytic or tumoral infiltration. NEC can develop with varying types of morphological involvement resulting in a highly variable clinical severity spectrum ranging from nonspecific abdominal symptoms to acute abdomen. Thus, diagnosis is very difficult and is only possible with a high suspicion index. It should rely on clinical data, which are unique, to assess the evolution and to indicate medical or surgical therapy. These therapeutic modalities should be individualized in each patient. All physicians treating neutropenic patients should be familiar with this condition and consider it in the differential diagnosis of abdominal pain.