Background: The purpose of this report is to describe ovarian paragonimiasis, a rare form of lung fluke infestation, mimicking ovarian cancer. Case: A 47-year-old Thai woman presented with a pelvic mass. Imaging suggested ovarian cancer with pulmonary and hepatic metastases. She was scheduled for complete surgical staging. However, a frozen section revealed Paragonimus eggs in the enlarged ovarian mass. A total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed instead of complete staging. All other lesions were also proven later to be Paragonimus infestation. Postoperative treatment with antiparasitic drugs resulted in dramatic improvement, with nearly complete resolution of all lesions at 4 months of follow-up. Conclusion: This is an unusual case of ovarian paragonimiasis mimicking ovarian cancer, which is instructive and informative for differential diagnoses of pelvic masses.