In 1987, 3227 diarrhea cases, half of which were infants, presented at the Out-patient Department of the Istanbul University Children's Hospital. An examination of these cases showed that in 1,066 cases diarrheal disease (DD) was accompanied by a coexisting infection or other disease. The cases with severe dehydration, shock or severe systemic disease were immediately hospitalized. All the remaining cases were administered oral rehydration therapy (ORT) in the Diarrhea Unit, and 94.7 percent of them were successfully rehydrated with ORT. Severe dehydration, shock, severe systemic infection, abdominal distention, failure of rehydration by the enteral route, severe protein energy malnutrition (PEM), and the presence of convulsions were the indications for i.v. therapy. The overall mortality rate was 11 percent. Our experience with DD indicates that widespread implementation of ORT in diarrheal disease and the establishment of Diarrhea Units in large hospitals will contribute not only to saving more lives but will also have an economic impact by reducing the number of admissions.