Proton pump inhibitor (PPI) monotherapy cannot cure all cases of gastroesophageal reflux disease (GERD), and combination therapy with prokinetics and PPI achieves symptomatic improvement for some GERD patients. Few studies have been performed to predict the need for prokinetics. Subjects were 163 patients (64 male, mean age 53.1 +/- 16.6 years) with GERD symptoms. They were evaluated using the frequency scale for the symptoms of GERD (FSSG), a GERD-specific questionnaire developed in Japan(1) and endoscopy. They were administered with rabeprazole 10 mg daily. At 12 and 24 weeks of treatment, subjects were offered a choice of four treatment regimens according to their degree of satisfaction (1, no need for further treatment; 2, opt for continued PPI treatment; 3, step-down to H2RA; 4, dissatisfied with present treatment, so opt for combination treatment with prokinetics, mosapride 5 mg tid). The choice of treatment after 12 weeks of treatment placed 79.1% of subjects in the satisfied group (1, 21; 2, 98; 3, 10). After 24 weeks, 98.2% of subjects were in the satisfied group. Pretreatment FSSG scores were significantly higher in the dissatisfied group (4, 17.4 +/- 1.4) than in the satisfied group (1, 12.3 +/- 1.3; 2, 12.8 +/- 0.8; 3, 10.2 +/- 1.8) (P < 0.05). The satisfaction rate with these treatment regimens was 98.2% at 24 weeks, suggesting that combination therapy with prokinetics was effective for patients dissatisfied with PPI monotherapy. The FSSG is a useful predictor of the necessity for combination therapy.