We herein report a 45-year-old Chinese male with a perforated jejunal gastrointestinal stromal tumor causing acute diffuse peritonitis and incomplete intestinal obstruction. At urgent laparotomy, a perforated tumor was found in the jejunum about 40 cm from the Treitz's ligament, and the upper small intestine was twisted 1080°. The clinical symptom of this case is extremely rare, and has not been reported in the literature previously.