Foreign body ingestion in small children is common. Multiple magnet ingestion is an unexpected health hazard that can lead to critical gastrointestinal injury. Magnets must be extracted, due to their high rate of complications, such as obstruction, perforation, and fistula formation. A 11-year-old boy with a history of autism was referred to the emergency room for abdominal pain and vomiting. X-ray examination revealed metallic objects in the upper abdomen, subsequently shown to be toy magnets. Fifteen small stick-shaped pieces had been attracted to each other to form a large triangle. The magnets were attracted to each other across the gastrointestinal wall which might have led to pressure necrosis, resulting in fistula formation. We removed eight toy magnets endoscopically with a detachable snare. The remaining 7 pieces were left in the duodenum for natural evacuation. He was discharged from the hospital on the 7th hospital day. X-ray examination confirmed release of all magnets on the 21st day. We think that if more than one magnet is found as a foreign body in the upper gastrointestinal tract, they should be removed endoscopically.