T-wave responses of biceps and triceps brachii muscles were recorded electrophysiologically from 31 normal subjects and 15 patients with unilateral lesions of the cervical C6 or C7 roots. Pathological T-wave responses were found in 11 (73%) patients. Patients with radiological correlate showed electromyographic (EMG) pathology in 60% but a pathological T-wave response in 90%. All patients with radiological correlate also showed pathological electrophysiological tests (EMG or T-wave responses). Electrophysiological measurement of the T-wave response appears to be a potentially useful tool in the diagnosis of cervical radiculopathies.