Single-fibre electromyography has become much easier because of the advantages offered by modern computerised EMG equipment. Fibre density, jitter and the frequency of blockings can thus be examined with relative reliability. The technique allows a sensitive diagnosis of disturbances of neuromuscular stimulus transmission. Furthermore, different pathological results obtained in patients suffering from neuropathies or myopathies (12 controls, 65 patients) proved the diagnostic value of single-fibre EMG. The method is a valuable addition to conventional EMG. The examination technique is described and illustrated by various examples.