We report an extremely rare case of primary ovarian Burkitt lymphoma. A 15-year-old girl was referred to our department because of persistent constipation and abdominal distension. Abdominal computed tomography and magnetic resonance imaging revealed a 10-cm-diameter solid tumor located on the right side of the uterus. Serum lactate dehydrogenase and carbohydrate antigen-125 levels were elevated at 3250 IU/L and 235.7 U/mL, respectively. Initially, ovarian dysgerminoma was suspected, but poor performance and progressive disease were suggestive of malignant lymphoma. However, bone marrow aspiration and ascitic fluid cytology findings were not indicative of lymphoma. Laparotomy was performed to confirm pathology. On laparotomy, the right ovary was firm and enlarged, but the uterus and left ovary were normal. Diffuse thickness of retroperitoneal space was observed. Right salpingo-oophorectomy was performed, and the tumor was diagnosed as Burkitt lymphoma. Although intensive chemotherapy was administered, the patient died 171 days after the initial operation.