A 45-year-old female was admitted with headache and vomiting. Cranial computed tomography (CT) demonstrated a callosal hematoma. Magnetic resonance imaging (MRI) showed no venous flow and thrombus replacing the inferior sagittal sinus (ISS) lumen. Under appropriate medical treatment and close follow-up she recovered quickly and, after 2 years, was doing well with corpus callosum infarcts. Isolated inferior sagittal sinus thrombosis is an extremely rare condition with only one previously reported case in the literature. Although it is very rare, isolated inferior sagittal sinus thrombosis should be considered in the differential diagnosis of non-traumatic corpus callosum hematoma.