Femoral nerve palsy seconder to iliacus hematoma has been rarely reported in terms of blood coagulation abnormalities, either from anticoagulant medications or from hemophilia. The clinical symptoms vary from femoral neuropathy to fatal hypovolemic shock with increased used of anticoagulant agents; femoral nerve palsy subsequent to hemorrhage within the iliopsoas muscle has become a frequent clinical problem. In our case, a 73-year-old male patient presented to hospital with left leg pain and weakness. Lumbar magnetic resonance imaging (MRI) and abdomen computed tomography (CT) showed a left-sided iliopsoas hematoma. An extraperitoneal inguinal incision (Gibson incision) was made. The hematoma was superior of the external iliac artery in the iliopsoas muscle. It was nearly 8 cm deep and was drained and evacuated. After the operation, the left leg pain decreased, and the weakness of left leg improved (3/5).