Abstract Rationale: Incomplete abortion often causes a lot of bleeding and may lead to severe anemia. The elevated beta-human chorionic gonadotropin (beta-hCG) level is often associated with a molar pregnancy. We report a case of incomplete abortion with elevated beta-hCG levels mimicking a molar pregnancy. Patient concerns: A 29-year-old woman experienced prolonged vaginal bleeding for several months. She had an artificial abortion one year before, however, vaginal bleeding was noted, and the local clinic prescribed progesterone and transamine to stop the bleeding. The amount of bleeding decreased after medication, but persistent bleeding was noted. Diagnosis: She visited our hospital where the urine pregnancy test was positive. Ultrasound and computed tomography showed a hematometra (4.5 cm × 4.3 cm), thickened endometrium, and mild ascites. An elevated serum beta-hCG level of 32980.4 mIU/mL was observed along with a hemoglobin level of 7.2 g/dL. Incomplete abortion or molar pregnancy was suspected. Interventions: Endometrial curettage was performed. Outcomes: Pathology showed the gestational product and chromosome analysis showed normal karyotyping. Incomplete abortion was diagnosed. Postoperative follow-up was uneventful and the beta-hCG level returned to normal after 3 months. Lessons: Incomplete abortion with elevated beta-hCG levels is a rare condition that mimics a molar pregnancy. Transvaginal ultrasound, quantitative serum hCG evaluation, and other laboratory tests (e.g., complete blood count) are essential preoperative investigations.