Gastroesophageal reflux is a frequent occurrence in infancy. Most frequently, gastroesophageal reflux (GER) is due to a functional disturbance and lack of coordination of esophageal motility and lower esophageal sphincter incompetence. Vomiting is the sole symptom in the great majority of infants and responds readily to postural and dietary therapy. A malposition and defective fixation of the cardia and abdominal esophagus is the pathophysiologic substrate of hiatus hernia. Although most patients with hiatus hernia have GER, hiatus hernia is only symptomatic with concomitant GER. Differentiation between hiatus hernia and GER should therefore be dispelled. Treatment of hiatus hernia with GER is directed towards placing the patient in an upright position, even 24 h a day if necessary in a patient severe symptoms. The duration of therapy can be weeks to months. Small, frequent feedings are of additional importance, while thickening of formula with cereals were found unnecessary. Over the last few years, we have been able to observe 22 infants under 1 year of age with GER and hiatus hernia. In 19 of these patients-among them also patients with reflux esophagitis-this conservative treatment regimen has been successful. Drugs like antacids or cimetidine to lower gastric were considered unnecessary. Bethanechol was considered contra-indicated due to its discomforting side effects in infants. Three patients have been treated surgically during this period of time. In contrast, hiatus hernia in older children-mainly mentally retarded children-with GER has to be treated surgically; conservative therapy is usually without effect. The rare clinical condition of brachyesophagus is considered a malformation and requires surgical therapy in every instance.