Spontaneous resolution of chronic subdural hematoma (CSDH) is rare, especially for the nontraumatic cases. Here, we present 1 case of a 70-year-old female patient with spontaneous resolution of CSDH. She was chronically anticoagulated after percutaneous coronary intervention. Moreover, she denied previous mild head trauma and bleeding episodes. For personal reasons, she declined surgery. Treatment just included mannitol, which was used to alleviate the symptoms. Intermittent computed tomography showed gradually resolution of CSDH. Spontaneous resolution of nontraumatic CSDH is rare, with different mechanisms and computed tomography characteristics compared with that of traumatic CSDH. Dimerized plasmin fragment D in venous blood may be more sensitive in the judgment of types of CSDH.