A prospective study including seventy-seven consecutive patients suspected of having ovarian tumoral or pseudotumoral pathology on CT was carried out. Fifty-nine patients had surgery with histological diagnosis. When comparing the CT and histological findings in benign and malignant lesions we obtained an overall accuracy of 95% with only three misdiagnosed cases on CT. False positive diagnosis of malignancy was established in a case of abdominal actinomycotic infection, a case of chronic appendicitis, and in a ruptured ectopic pregnancy. These three cases are discussed in detail.