Abstract: Massive enlargement of an ovarian cyst is an uncommon cause of morbidity and a rare cause of mortality due in large to part to noninvasive imaging techniques that usually permit early detection. When an ovarian cyst reaches giant proportions, it produces abdominal enlargement often with a fluid wave resulting in a condition that mimics ascites, called pseudoascites. Despite their impressive appearances, such cysts often are operable for cure. We describe a case of a middle-aged woman who presented 3 years before her death with symptoms from an undiagnosed giant cyst and given a diagnosis of ascites of undetermined etiology. She subsequently died at home unexpectedly, and at autopsy, she was found to have a massively enlarged but otherwise benign mucinous cystadenoma.