In two patients with the Lambert-Eaton myasthenic syndrome (LEMS) and small-cell lung carcinoma (SLLC), therapy for LEMS was effective when combined with cancer therapy. The serial SFEMG tests showed a corresponding improvement with remission of the LEMS and proved to be a better and earlier indicator of the changing clinical status than the repetitive nerve stimulation test. Thus, we conclude that the SFEMG is useful in the follow-up evaluation of patients with this condition.