Acute pediatric abdomen is a very common clinical problem. Clinical and laboratory findings, however, are nonspecific or confusing in many instances. This exhibit focuses on strategy in diagnosing acute pediatric abdomen depends on age. Age is a key factor in evaluating the cause; the incidence and symptoms of different conditions vary greatly over the pediatric age spectrum. We divided pediatric age into three groups (before 1 year, 2 to 5 years, over 6 years). A variety of diseases are discussed in this exhibit, such as before 1 year (intussusception, midgut volvulus, incarcerated hernia, congenital biliary dilatation, gastroenteritis), 2 to 5 years (appendicitis, mesenteric lymphadenitis, Henoch-Schonlein purpura, trauma), over 6 years (pancreatitis, cholecystitis, hemorrhagic ovarian cyst, ovarian torsion). Ultrasonography is essential to ensure prompt management and can provide specific diagnoses. Acute pediatric abdomen is a very common clinical problem. Clinical and laboratory findings, however, are nonspecific or confusing in many instances. This exhibit focuses on strategy in diagnosing acute pediatric abdomen depends on age. Age is a key factor in evaluating the cause; the incidence and symptoms of different conditions vary greatly over the pediatric age spectrum. We divided pediatric age into three groups (before 1 year, 2 to 5 years, over 6 years). A variety of diseases are discussed in this exhibit, such as before 1 year (intussusception, midgut volvulus, incarcerated hernia, congenital biliary dilatation, gastroenteritis), 2 to 5 years (appendicitis, mesenteric lymphadenitis, Henoch-Schonlein purpura, trauma), over 6 years (pancreatitis, cholecystitis, hemorrhagic ovarian cyst, ovarian torsion). Ultrasonography is essential to ensure prompt management and can provide specific diagnoses.