Apparent life-threatening events in an infant require: 1/ to determine the seriousness of the event; 2/ to identify its etiology; 3/ to evaluate the risk of recurrence and the need for appropriate preventive measures. Management mainly depends upon the determination of the etiology and the understanding of the pathogenetic mechanism. Gastroesophageal reflux is the main etiology. Therefore whenever symptoms of gastroesophageal reflux are present, this has to be considered as the first etiological hypothesis. Other etiologies will be searched for if orientating symptoms or anamnesis information is present, leading to specific investigations.