We used a simple questionnaire to determine the presence or absence of symptoms of gastroesophageal reflux disease (GERD) among control (n=531) and diabetic patients (n=629). Of 531 controls, 24.3% reported having symptoms, while 24.9% of 629 diabetic patients had symptoms. Symptomatic diabetic patients (n=157) were then asked to complete a supplemental questionnaire (QUEST) to determine the frequency, severity, and duration of GERD symptoms; a total diagnostic score > or =4 was considered to be positive for GERD. Diabetic patients whose QUEST score was > or =4 had a significantly higher BMI (26.9+/-0.4* vs. 24.4+/-0.4), higher HbA1c (7.5+/-0.2* vs. 7.2+/-0.1), longer duration of diabetes (113.5+/-8.7* vs. 94.0+/-10.6 months), and a higher prevalence of diabetic complications (retinopathy, 24.8%* vs. 21.3%; nephropathy, 32.6%* vs. 19.4%; neuropathy, 30.4%* vs. 23.6%) than diabetic patients whose QUEST score was <4 (*p<0.05). In diabetic patients with GERD, therapy should include not only proton pump inhibitor therapy and other specific measures for GERD, but also appropriate therapy for the diabetes, particularly blood glucose control and weight reduction.