OBJECTIVE: To alert about the pseudomembranous colitis in children, a consequence of the use of antibiotics. METHODS: This report is the result of the clinical follow-up of a patient with chronic diarrhea after the use of several antibiotics. The bibliography was obtained through Medline system. RESULTS: Case report of a girl two years and seven months old, previously healthy, with a clinical picture of chronic diarrhea with dysenteric characteristics after the use of antibiotics, associated with important weight lost and hypoproteinemia. The diagnosis of pseudomembranous was established clinically and was confirmed by colonoscopy and the presence of Clostridium difficile toxin A in the stools. CONCLUSIONS: It is necessary to consider the C. difficile infection in any child with diarrhea associated to the use of antibiotics. The antibiotics in pediatric patients should always be prescribed with caution and precise indications.