Rationale:Anastomosing hemangioma (AH) is a rare benign neoplastic vascular lesion that histologically resembles a well-differentiated angiosarcoma. AH commonly involves the urinary system and testes. However, these tumors can also involve the ovaries in some rare cases. This manuscript presents the case of a 28-year-old Chinese woman diagnosed with ovarian AH.Patient concerns:The woman was admitted to the hospital with a 4-month history of a right ovarian mass discovered by ultrasound (US) after a spontaneous abortion. The US examination showed a 4 cm × 4 cm irregularly shaped mass with a rich blood supply.Diagnoses:AH of the right ovar.Intervention:The patient underwent laparoscopic surgery to remove the mass. The postoperative pathological examination revealed that the mass contained capillaries arranged in a characteristic anastomotic or confluent pattern commonly seen in AHs.Outcomes:The mass was successfully removed. The follow-up examination at 7 months post-surgery showed that the patient recovered well, and no recurrence or metastasis was found.Lessons:AH of the ovary is a rare benign vascular tumor. On imaging examinations, AHs appear as mostly well-defined, heterogeneous nodules with peripheral enhancement as other benign nodules. However, a definitive diagnosis can only be achieved through histopathological examination.