Multiple symptoms suggestive of gastroesophageal reflux (GER) developed in 181 of 240 children (75%) with profound neurological impairment (NI) following operative management of GER. Diagnostic testing was performed in 102 children, 56% of patients with symptoms. Recurrent GER was evident on one or more diagnostic studies in 46% of children evaluated. Significant differences (P less than .05) were found in the testing protocols of children with studies positive for GER and those individuals with negative tests. Children with study-documented recurrent GER: (1) had testing conducted at a more remote time postoperatively; (2) received a greater number of total tests; (3) were evaluated by more than one type of diagnostic test; and (4) underwent upper endoscopy and pH monitoring more frequently. No single clinical symptom was predictive of study-documented recurrent GER. These results suggest that recognition of recurrent GER after an antireflux operation in a child with profound NI requires a high index of suspicion. Definitive evaluation of children with postoperative symptoms demands repeated testing over time and the use of more than one type of diagnostic test. A contrast study should be used to evaluate the mechanical properties of the fundoplication and esophagoscopy and/or esophageal pH monitoring to assess the physiological control of GER.