Infants [15] with symptoms of gastroesophageal reflux (GER) were evaluated with esophageal manometric studies. Six infants failed on a medical regimen of frequent thickened feedings and an upright position 24 h/day for 3 wk. These infants had Nissen fundoplications. Their mean lower esophageal sphincter (LES) pressure was 12.7 mm Hg. The 9 infants who did well on the medical regimen had a mean LES pressure of 19.6 mm Hg. These means are significantly different (P. < .001). Esophageal manometric studies should be included in the evaluation of all infants with symptoms of chronic GER.