A 15-year-old boy, with a diagnosis of hemophilia A, suffered bleeding into his left forearm 5 months before being admitted to our medical center. His neurological examination revealed a pronounced median neuropathy and a minor ulnar neuropathy on the left side. There was marked muscle atrophy on the thenar side and, to a lesser degree, on the hypothenar side and in the forearm. Electromyographic findings demonstrated an evident, nearly complete, sensorimotor axonal loss in the median nerve. Magnetic resonance imaging studies showed atrophy in muscles of the left forearm and median nerve. The patient was diagnosed as having median nerve axonotmesis and ulnar nerve neuropraxia due to compartment syndrome. In hemophiliac patients, frequent single nerve compressions (often involving the femoral nerve) can be seen. However, concomitant median and ulnar nerve injuries with differing severity are rare. Joint Bone Spine 2002; 69 : 611-3. (C) 2002 Editions scientifiques et medicales Elsevier SAS.