OBJECTIVES: The aim of this observational study was to gather epidemiological data not yet available in Luxembourg in a primary care patient population with GERD with a history of erosive esophagitis (≤ 3 years) and to evaluate the supposed added value of the GERD Impact Scale (GIS) as a useful tool for initial and follow-up long-term patient management of GERD. The GIS (score range 1–4) is a novel patient questionnaire designed to aid physicians to identify the appropriate treatment and to evaluate the patient’s response to treatment. METHODS: Consecutive patients from 20 study centers with symptomatic GERD with or without esophagitis grade A to D (Los Angeles classification) were included. The physician decided at inclusion whether to initiate or change the GERD treatment. Exclusion criteria included current use of proton pump inhibitors (PPIs). Patients’ symptoms, general evaluation by the physician, treatment changes and GIS were assessed at baseline (visit 1) and visits 2 and 3 (4–6 weeks and 8–14 weeks, respectively). Analyses were performed on an intent-to-treat basis. GIS scores were obtained by the physician at each visit. RESULTS:  A total of 142 patients with visit 2 data available for ITT analysis (152 patients enrolled) were included (mean age 48 years, 51% female, mean BMI 27 kg/m2, 75% sedentary lifestyle). Upon inclusion, 21% had never received any treatment, 44% were receiving, or had received antacids, 21% H2-receptor  blockers, 46% had received PPI therapy proton pump inhibitors (PPI) therapy (34% omeprazole, 31 esomeprazole, 21% pantoprazole, 11% rabeprazole, 3% lansoprazole).  After visit 1 physicians changed treatment in favor of full-dose PPIs (94% of cases), mainly esomeprazole (75%) and stopped almost all h2-receptors blockers (1%). Seventy-five percent of patients were in acute phase treatment after visit 1 which changed to maintenance treatment phase in 91% of patients after visit 3. There was a concomitant dose reduction of 40 mg to 20 mg for the most prescribed PPI esomeprazole. Forty-percent of patients became The prescribed dose was changed to a median of 20mg at visit 2 in 32% of patients. The severity of GERD symptoms decreased substantially throughout the study with 84% of patients having moderate or severe GERD in visit 1, 23% in visit 2 and 11% in visit 3. Concurrently, the GIS scores decreased significantly (-1.27 for upper GI symptoms, -0.92 for other related GI symptoms and -0.85 for the impact on life; p<0.001). The GIS was judged to be helpful for approximately 80% of the patients by the physicians. At all visits, the GIS mean-scores increased markedly with increasing severity of disease (clinical judgment). The correlation between GIS mean-scores and endoscopy findings or the physician’s judgment of the usefulness of the GIS was less pronounced. CONCLUSIONS: GIS scores improved with GERD PPI treatment and were judged helpful by the physician. GIS may thus have an added value over these assessments in determining the appropriate treatment and evaluating the patient’s response to this treatment.