A 13-year-old boy, complained of an intermittent suddenly aggravated severe abdominal pain and diarrhea, was diagnosed as a small bowel volvulus without an intestinal malrotation, due to mesenteric lymphangioma. He took abdominal ultrasonography, abdominal CT scanning, upper gastrointestinal study and got an operation. The small bowel volvulus with cystic lymphangioma was confirmed by gross and pathologic findings.