The data from the charts of 109 infants who were younger than 9 months of age and who had been hospitalized with acute diarrheal syndrome in 1978 were compared with data from the charts of 108 healthy infants of the same age range with the same sex and ethnic distributions who were attending well-child clinics serving the same geographic area during the same year. In a comparison of weight percentiles, 45.3% of the acute diarrheal syndrome patients and 11.3% of the well children were below the 10th percentile. When height percentiles were compared, 41.8% of the acute diarrheal syndrome patients and 15.3% of the well children were below the 10th percentile. The data indicate that malnutrition was a characteristic of infants with acute diarrheal syndrome who required hospitalization.