Abstract. Adult sporadic Burkitt lymphoma (BL) is a rare aggressive neoplasm and represents ~1-5% of all lymphomas diagnosed in adults. The disease exhibits an aggressive clinical manifestation, which frequently involves the central nervous system (CNS) in the early stages, and is usually accompanied by abnormalities in cerebrospinal fluid (CSF) examinations and/or neuroradiography. The current study describes the rare case of a 29-year-old man who presented with oculomotor nerve palsy without palpated masses, B symptoms, peripheral blood anomaly and abnormalities of the nervous system. The patient was initially misdiagnosed with abducens diplopia, but was subsequently confirmed to have BL with early CNS invasion. Epstein-Barr virus and human immunodeficiency virus infection were negative. Intensive systemic chemotherapy with hyperfractionated cyclophosphamide, vincristine, therarubicin and dexamethasone (hyper-CVAD, cyclophosphamide 600 mg/m 2 on days 2-4; vincristine 1.4 mg/m 2 on days 5 and 12, therarubicin 50 mg/m 2 on day 5 and dexamethasone 40 mg on days 2-5 and 12-15), including intrathecal chemotherapy with methotrexate (5 mg), arabinocytidine (5 mg) and dexamethasone (5 mg), was determined as an appropriate treatment. Rituximab (375 mg/m 2 on day 1) was administered alongside chemotherapy to increase treatment efficacy. The patient temporarily underwent complete remission, but subsequently relapsed as no suitable bone marrow donor was available. Adult sporadic BL with early CNS invasion, which traditional tests such as neuroradiography and CSF examination fail to identify, is uncommon. Therefore, appropriate diagnostic tests are critical for accurate diagnosis and must be performed immediately, particularly in patients that present with unusual image and laboratory manifestations.