Non-gestational choriocarcinoma (NGCO) of the ovary is rare, with a prevalence of less than 0.6% of all ovarian germ-cell tumors; and when found with other germ cell tumors, pure NGCO is exceedingly rare. We herein report the case of a 22-year-old woman who complained of menstrual disorders for over 2 months. MRI examination revealed an 11.4 cm right adnexal mass of the uterus, and the patients manifested an elevated serum level of β-hCG of 77,928 mIU/ml. Fertility-preserving surgery was performed, and the pathologic diagnosis was pure NGCO; immunohistochemical staining showed cancer cells that were positive for β-hCG, CK, hPL, SALL4, and Ki-67 (>80% of cells stained). We performed polymorphic DNA analysis and non-gestational origin was confirmed. The patient was then treated with six courses of chemotherapy with a BEP regimen, after which her serum β-hCG levels declined to normal levels, and she was free of disease at the 30-month follow-up.