Generally infrapatellar region is innervated by the infrapatellar branch of the saphenous nerve and the branches of medial cutaneous femoral nerve that form a plexus so called subsartorial plexus. We found that saphenous nerve after leaving the adductor canal did not give an infrapatellar branch but the whole sensory nerves of the infrapatellar region were originating from medial cutaneous femoral nerve in a cadaver. A detailed anatomic knowledge about the innervation of the infrapatellar region is mandatory for knee surgeons. Surgeons should always consider the extreme variability of infrapatellar innervation and should pay extra attention to protect the innervating nerve during dissection.