The purpose of this study was to document the psychometric characteristics of the Japanese translation of the Quality of Life in Reflux and Dyspepsia (QOLRAD-J) questionnaire in patients with heartburn.Patients with heartburn or acid regurgitation and healthy subjects completed the QOLRAD-J and the Japanese version of the Short-Form 36-Item (SF-36) Health Survey.Overall, 224 patients with heartburn and 24 healthy subjects entered the study; 72% of patients had heartburn 1-3 days per week; 84% reported their symptoms as mild. Psychometric validation of the QOLRAD-J showed that factor loadings were >0.55 for 19 of the 25 items in the five-factor structure. Pearson correlation coefficients for inter-item correlations in the same domain were all >0.30, demonstrating reliability. The internal consistency reliability was good (Cronbach's alpha, 0.83-0.94). Inter-item correlations between domains ranged from 0.70 to 0.80, indicating strong correlations. Each QOLRAD-J domain correlated positively with at least five of the eight SF-36 domains (Pearson r >or= 0.3). Negative correlations between the QOLRAD-J and patient-reported frequency and severity of heartburn symptoms indicated decreasing quality of life with increasing symptoms. All domains of the QOLRAD-J were able to differentiate between groups of patients whose health status differed according to severity and frequency of heartburn, thus confirming the known-groups validity. Patients with heartburn had clinically significant decreases in SF-36 scores compared with the Japanese general population.The psychometric characteristics of the QOLRAD-J demonstrated good validity and reliability. The QOLRAD-J can be used to assess quality of life in Japanese patients with heartburn.