Gastroesophageal reflux (GER) is usually defined as a physiological passage of stomach contents back into the esophagus. It is most prevalent in infancy, and occurs in up to 90 % of infants. The prevalence gradually decreases with age. Gastroesophageal reflux disease (GERD) is a complication of GER when it creates troublesome symptoms. It is estimated that GERD can be diagnosed in up to 20 % of adolescent population, which is close to adult numbers. GERD can present in a wide range of esophageal and extraesophageal symptoms. A detailed clinical and family history and a thorough physical examination are usually enough for diagnosis of GERD. When diagnosis is unclear or complications are suspected investigations could be performed: upper gastrointestinal (GI) endoscopy with biopsies, pH/impedance monitoring, abdominal ultrasound, laryngoscopy, sometimes contrast radiography, brain MRI, etc. The differentiation of GERD should be between GI diseases of different etiology: anatomical defects, inflammation, allergy, stress and extraesophageal diseases: brain tumors, hydrocephalus, psychiatric disorders, metabolic diseases, intoxication, kidney failure, etc. The first-line treatment of GERD in children and adolescents includes modifying the diet and lifestyle (reduction of psychological stress and gaming, increasing sleep duration, appropriate physical activity, etc.). The main medications are proton pump inhibitors which poorly works in infants and are quickly metabolized in children so needs high doses. In milder cases alginates could be used. New medications failed to reach good response in the treatment of GERD (prucalopride, intrapyloric Botulinum toxin injections, neuromodulators, etc.).