Nosocomial diarrhea are an important cause of childhood morbidity and mortality. Rotavirus has been recognized as the most important cause of nosocomial gastroenteritidis particularly in infants during winter months. Nosocomial diarrhea are also, caused by bacterial pathogen like Clostridium difficile, Salmonella, Shigella, Campylobacter. Clostridium difficile toxin assay should be considered for patients who are receiving antibiotics. Modifications of hygiene procedures and preventive measures are necessary in order to reduce nosocomial infection.