Background: Gastroesophageal reflux disease is thought to be the commonest cause of 'non-cardiac chest pain'. The use of proton-pump inhibitors resulting in improvement in the chest pain symptom would support this causal association., Objectives: To determine the prevalence of gastroesophageal reflux disease in non-cardiac chest pain and the response of chest pain to proton-pump inhibitor therapy., Methods: Patients with recurrent angina-like chest pain and normal coronary angiogram were recruited. The frequency and severity of chest pain were recorded. All patients underwent esophagogastroduodenoscopy and 48-h Bravo ambulatory pH monitoring before receiving rabeprazole 20 mg bd for 2 weeks., Results: The prevalence of gastroesophageal reflux disease was 66.7% (18/27). The improvement in chest pain score was significantly higher in reflux compared to non-reflux patients (P = 0.006). The proportion of patients with complete or marked/moderate improvement in chest pain symptoms were significantly higher in patients with reflux (15/18, 83.3%) compared to those without (1/9, 11.1%) (P < 0.001)., Conclusion: The prevalence of gastroesophageal reflux disease in patients with 'non-cardiac chest pain' was high. The response to treatment with proton-pump inhibitors in patients with reflux disease, but not in those without, underlined the critical role of acid reflux in a subset of patients with 'non-cardiac chest pain'.