Aim: To describe the endoscopic findings in adult patients subjected to esophagogastroduodenoscopy (EGD) for the evaluation of heartburn, and establish a relationship between the presence of a hiatal hernia and erosive esophagitis. Patients and Methods: We reviewed the endoscopic reports of all the patients older than 16 years old who were evaluated for heartburn in our institution, between December 1998 and December 2001. The statistical analysis to establish the relationship between Hiatal Hernia (HH) and Erosive Esophagitis (EE) was performed calculating the Odds Ratio (OR). Results: A total of 1270 outpatient EGD were performed in the study period, of which 345 (27%) had persistent heartburn as the indication for the procedure. There were 174 females (50.43%) and 171 males (49.57%). Erosive esophagitis was diagnosed in 151 (44%). Fifty-eight (17%) patients had EE in the absence of a HH, 63 (18%) had HH in the absence of EE. Ninety-three patients (27%) had both HH and EE, 20 (6%) of patients had histologically confirmed Barrett's esophagus, 91 (26%) had other nonrelated findings such as antral gastritis and 36 (10%) had normal EGD. Of 156 patients with HH, 93 (59.6%) had also EE, whereas EE was present only in 58 of 189 (30.6%) patients who did not have HH, obtaining an OR of 3.33. Conclusions: Most of our patients with heartburn didn't have erosive esophagitis. In our series, patients with heartburn and a hiatal hernia have a three-fold risk of having erosive esophagitis compared with patients with heartburn and no hiatal hernia.