We report case of primary volvulus of the small intestine and review 15 cases from the Japanese literature. A 56-year-old woman, with a history of appendectomy 30 years previously, was admitted with abdominal distension and signs of peritonitis. Abdominal computed tomography (CT) demonstrated a whirl-like pattern of the mesentery, showing the tightly twisted mesentery around the point of torsion. An emergency laparotomy revealed strangulation of the small intestine, from 200 cm anal to the Treitz ligament to 5 cm oral to the terminal ileum, caused by 360 degrees clockwise torsion. There was no adhesion caused by the previous operation nor were there any congenital anomalies. The strangulated intestine was removed and jejunocolonostomy was performed. The patient was discharged from hospital on day 39 after the operation. Primary volvulus of the small intestine was reported to be rare in Japan, but the mortality was 26%. Immediate diagnosis and surgical intervention is essential to achieve a good outcome. A whirl-like pattern of the mesentery is a typical sign of this condition on CT.