Pediatric acute appendicitis is the most common disease in pediatric abdominal surgery. Generally speaking, the condition is more serious than that of adults. Therefore, timely diagnosis and proper treatment of pediatric acute appendicitis is important. In infants, the appendix is funnel-shaped, with a wide opening at the base and smooth drainage, and after the age of 2 years, the appendiceal cavity becomes thinner, and by school age the appendix is almost indistinguishable from that of adults. The younger the appendiceal cavity, the larger the cavity, but the thinner the wall, the less muscle tissue, and the faster the necrosis and perforation due to impaired blood flow. Therefore, the chance of acute appendicitis with perforation is higher in pediatric patients than in adults. Because the large omentum in pediatric patients is thin and short, it is less able to confine inflammatory lesions, and once perforated, diffuse peritonitis occurs rapidly. Abdominal pain is one of the main symptoms of pediatric acute appendicitis. It starts mostly around the umbilicus or in the upper abdomen and shifts to the right lower abdomen after a few hours or after a night. In some cases, the abdominal pain starts in the right lower abdomen, especially in acute episodes of chronic appendicitis, and the pain is mostly persistent and dull in nature, with episodic exacerbations. If there are severe paroxysmal colic, this often indicates an obstruction in the appendiceal cavity. In acute appendicitis, many children prefer to lie on their right side with their legs slightly flexed, choosing the position with the least pain. Sometimes the child lies on his or her back, but rarely on the left side. This is because the appendix with an inflamed appendix and prolapse can cause pain. In addition, any movement may increase intra-abdominal pain, so the child chooses a position and then tries to maintain that position. Clinical signs of appendicitis in infants are often atypical and difficult to diagnose. Any child with noisy abdominal pain, unexplained vomiting and fever should be thought of as having this disease. In infants with appendicitis, vomiting is a frequent symptom and often precedes abdominal pain, and a history of diarrhea is more common than in older children. The lesion progresses rapidly and perforation can occur within 12 hours, resulting in diffuse peritonitis. Children are usually admitted with a high fever and more marked abdominal distention. Abdominal pressure pain is widespread, often covering the entire lower abdomen or even the whole abdomen. It is relatively mild and vague in extent, rarely confined to the right lower abdomen as in older children. Pediatric appendicitis is more serious and parents should be aware that they should go to a regular hospital immediately if the above symptoms appear. Early removal of the appendix is necessary to avoid the spread of infection.