Vomiting can be the presenting symptom of a variety of disorders, ranging from self-limited diseases to life-threatening diseases. The causes of vomiting vary with age of presentation, and pediatricians should develop the skill to identify serious conditions at the earliest stage based on the age of presentation. Bilious emesis at any age is a sign of intestinal obstruction until proven otherwise and needs immediate attention. Vomiting is not always due to a GI disorder, and pediatricians should look for causes outside the GI tract if no GI disease is identified.