Primary torsion of the greater omentum is a rare cause of acute abdomen commonly diagnosed at surgery performed for appendicitis. We report nine cases of omental torsion who underwent surgery and correlate their preoperative color Doppler ultrasonography (US) and computed tomography (CT) findings with the surgical and pathological findings to assess the value of US and CT in the diagnosis of omental torsion. US findings of omental torsion correlated with the operative and pathological findings in seven patients and the diagnosis was missed in two patients suspected to have ruptured appendix. CT findings of omental torsion correlated with the operative and pathological findings in all five patients who did CT. US and CT scanning are useful for preoperative diagnosis of omental torsion.  2014 Production and hosting by Elsevier B.V. on behalf of Egyptian Society of Radiology and Nuclear Medicine.