Elevated serum CA125 levels may be caused by any condition which produces peritoneal irritation as well as by the presence of various malignancies. This report of a case with atypical presentation of tubo-ovarian abscess and CA125 level of 1,160 U/ml serves to re-emphasize cautious operative planning in patients desirous of reproductive capability in the face of findings highly consistent with probable malignancy. This is the highest reported serum CA125 level in a reproductive age woman with well-documented reversible benign disease.