Multiple sites of compression of the radial nerve have been described, some more commonly than others. In this case report we describe a case of radial nerve compression at the lateral intermuscular septum in a patient with a history of open reduction and internal fixation of a mid-shaft humerus fracture 10 years prior. To our knowledge, only one previous case of chronic radial nerve compression by the lateral intermuscular septum associated with a humeral shaft fracture has been described. Our patient’s clinical presentation with specific electrodiagnostic abnormalities, operative findings and post-operative symptom relief point towards the rare diagnosis of compression of the radial nerve at the level of the lateral intermuscular septum as the cause of his symptoms.