Endoscopy is the method commonly used in the diagnosis of GERD (Gastroesophageal Reflux Disease). Although it is not rare that despite of typical clinical symptoms of the disease, investigation doesn't show any changes. The aim of endoscopy is to monitor pathological changes occurring in GERD--severe inflammation of the esophagus, strictures, ulcers and Barrett's esophagus. The possibility of histopathological assessment of mucosal biopsy, allows us to find dysplasia or metaplasia changes. Proton pump inhibitors (PPI) are first choice drugs in GERD and show higher efficacy compared to H2 blockers and prokinetic drugs.