Background and aim. Dental erosion (DE) represents a frequent condition in adults and the elderly. The gastroesophageal reflux disease (GERD) is considered an important endogenous factor causing dental erosions. The objective of this study was to assess the prevalence of DE in GERD patients and to establish the correlation between pathogenic intrinsic and extrinsic factors of DE and their relation to GERD. Methods. A cross-sectional study was conducted on 263 patients (median age 43). Patients with heartburn were recruited in two countries with different prevalence of GERD. Patients were recruited from France (n=158, 60%) and Romania (n=105, 40%) including 163 females and 100 males. The Basic Erosive Wear Examination (BEWE) index for diagnosis and evaluation of dental erosion was used. Based on the value of BEWE score, each patient was included in a risk group for DE development (low risk: BEWE=3-8, medium risk: BEWE=9-13, high risk: BEWE ≥14). Patients filled a questionnaire regarding GERD symptoms, medications, life style. Salivary parameters (pH and buffering capacity) were also assessed and analyzed. Results. DE was significantly more frequent and more severe in GERD subjects than in the non-GERD controls. Low salivary pH but not salivary buffering capacity was associated with BEWE scores. Buffering capacity however was significantly more altered in patients with BEWE score over 9 (medium DE) than in patients with mild DE (BEWE <9). Although extrinsic factors (consumption of citrus fruits, soda drinks) were associated with DE in GERD, there was no statistical correlation with the BEWE score. From the total of 263 patients, 229 (87.1%) presented BEWE score <9, and 34 (12.9%) presented BEWE ≥9. The DE was significantly associated with the presence of GERD (p<0.001). BEWE score >9 was more frequently present in GERD patients (30 patients: 21.3%) than in non GERD patients (4 patients: 3.3%). DE were more frequent in French subjects compared to Romanian subjects. Romanians had lower BEWE scores than the French. Conclusions. DE is more frequent and more severe with GERD vs. non-GERD. DE in GERD is associated with extrinsic dietary factors like citrus fruits and soda drinks.