Left alien hand sign and mirror writing after left anterior cerebral artery infarction. A 43-year-old, right-handed man was admitted complaining of peculiar movements of his left hand. Computed tomography scan and magnetic resonance imaging showed an infarct area in the territory of the left anterior cerebral artery. The abnormal movements of the left hand were diagnosed as so-called alien hand sign. This patient also exhibited mirror writing with his left hand. The clinical manifestations and neuroradiological findings of this case are described in detail, and the possible mechanisms of these extremely rare combinations of alien hand sign and mirror writing are discussed. 