Barium sulfate is widely used for gastroenterology imaging. Retention of barium in the appendix, where it acts as an appendicolith, thereby leading to obstruction and inflammation. Barium-associated appendicitis is a very rare complication of upper gastrointestinal imaging (UGI), especially in children. We present a case involving an 8-year-old girl who was diagnosed with acute appendicitis due to a barolith and required a laparoscopic appendectomy 6 weeks after UGI. After UGI, patients should be informed regarding possible retention of barium in the appendix, which can cause acute appendicitis. Then, a laparoscopic appendectomy was performed successfully. We should be cautious of this potential risk to prevent complications with early intervention in children.