Meigs' syndrome is defined as a hydrothorax with ascites and a pelvic tumor, both of which resolve on removal of the tumor. Pseudo-Meigs' is a variant not possessing the original tumor cell types described by Meigs. Both these syndromes should be considered in otherwise healthy women who present with either new or recurrent hydrothorax and ascites. This case concerns a 21-year-old woman who presented to the emergency department (ED) with a recurrent hydrothorax. After performing a pelvic examination that was suspicious for a pelvic mass, further evaluation by ultrasonography showed ascites and a pelvic tumor. Surgeons from the Obstetrics and Gynecology Department performed an exploratory laparotomy with removal of the tumor. Subsequently, there was no recurrence of the ascites and hydrothorax. The tumor was diagnosed histologically as a benign mature teratoma. The literature of Meigs' and Pseudo-Meigs' is reviewed, focusing on the history, pathology, and clinical characteristics. The clinical significance for the emergency physician is discussed.