Gastroesophageal reflux (GER) is a common cause of vomiting in childhood. The prevalence of troublesome GER disease is 5-8% in adults as well as in children. Many factors contribute to competency of the gastroesophageal sphincter and development of symptoms. In this article we describe possible mechanisms and clinical symptoms of gastroesophageal reflux. Methods of investigation and management of GER will be discussed.