Pseudomembranous enterocolitis is reported in five children. The clinical syndrome, characterized by the acute onset of profuse diarrhea, occurred postoperatively in 2 patients. All the patients had received or were taking antibiotics (penicillin, ampicillin, clindamycin). The disease was severe in 4 persons who presented with hypoproteinemia. Related complications were edema, ascites, pleural effusion, septicemia and/or shock. The diagnosis was made on the basis of typical rectosigmoidoscopic findings. Despite intensive therapy 2 children died. The use of parenteral nutrition is advocated in severe cases with exudative enteropathy. When profuse diarrhea occurs postoperatively or does not rapidly subside with discontinuation of antibiotic therapy, a high index of suspicion should be maintained, even in children, for the possibility of pseudomembranous enterocolitis. An emergency rectosigmoidoscopy should be done in order to make an early diagnosis.