To determine whether thickening of infant formula feedings with rice cereal increases coughing, we studied 25 infants from birth to 6 months of age, referred for evaluation of gastroesophageal reflux. Coughing was blindly quantified after each of a pair of isocaloric meals (one thickened and one unthickened). Coughing was more frequent after thickened feedings than after unthickened feedings.