To determine the risk factors and clinical presentation of primary omental torsion (POT) in children. Histopathology records of a pediatric hospital from January 1993 to March 2003 were reviewed to identify cases of POT. Hospital charts of patients diagnosed with POT were reviewed for demographic data and clinical presentation. A diagnosis of POT was recorded in 12 of 41,987 pathology records reviewed. Most of the patients were white (92%), male (75%), and 9 to 16 years old (75%). Weight percentiles were >or=95th in 11 (92%) of 12 patients. Body mass index was calculated in 9 of the 12 cases with 8 >95th percentile. Clinical presentation including right-sided abdominal pain, tenderness, and anorexia closely mimics acute appendicitis. Obesity seems to be an important risk factor for POT in children. The presentation for POT seems to be less acute than with other causes of surgical abdomen.