BACKGROUND: The low FODMAPs (fermentable oligo-, di-, monosaccharides, and polyols) diet improves lower gastrointestinal symptoms. Patients suffering from proton pump inhibitor (PPI) refractory gastroesophageal reflux disease (GERD) have limited treatment options. We investigated the efficacy of a low FODMAPs diet in patients with PPI refractory GERD. METHODS: This multicenter, randomized, open-label study compared the efficacy of a 4-week low FODMAPs diet and usual dietary advice (ie, low-fat diet and head of bed elevation) in patients with symptomatic PPI refractory GERD, defined by a Reflux Disease Questionnaire (RDQ) score >3 and abnormal pH-impedance monitoring on PPIs. The primary endpoint was the percentage of responders (RDQ ≤3) at the end of the diet. RESULTS: Thirty-one patients (55% women, median age 45 years) were included, 16 randomized in the low FODMAPs diet group and 15 in the usual dietary advice group. Adherence to the assigned diet was good, with a significant difference in the FODMAPs intake per day between the low FODMAPs diet (2.5 g) and the usual dietary advice group (13 g) (p < 0.001). There was no difference in response rates (RDQ score ≤3) between the low FODMAPs diet (6/16, 37.5%) and usual dietary advice (3/15, 20%) groups (p = 0.43). Total RDQ score and dyspepsia subscore decreased significantly over time in both groups (p = 0.002), with no difference according to the assigned diet group (p = 0.85). CONCLUSION: Low FODMAPs diet and usual dietary advice have similar but limited beneficial effects on symptoms in patients with PPI refractory GERD.