Omentum torsion is a rare cause of acute abdomen. Omentum torsion generally takes place on the right side and clinically mimics appendicitis, so for this reason omentum torsion is generally diagnosed by laparatomy carried out for appendicitis. For differential diagnosis from appendicitis it is important that pain starts suddenly after a heavy meal or hard exercise in omentum torsion and also pain is not accompanied with nausea, vomiting and anorexia. A 54 year-old female patient with suspected appendicitis was operated on and a right paramedian incision was employed. Primary omentum torsion was diagnosed and the infarcted tissue resected. We suggest that in cases where acute appendicitis is uncertain omentum torsion and other pathologies must be considered. In these cases a paramedian incision and diagnostic laparascopy may provide benefit for diagnosis.