In a case with small cell carcinoma of lung, typical features of Parinaud's syndrome were seen. MRI and EEG revealed no involvement of central nervous system. Tests for specific infections and connective tissue diseases did not indicate abnormal findings. No electrophysiological findings suggesting the involvement of the peripheral and neuromuscular systems were seen using EMG-NCV measurements and repetitive electrical stimulations. Although no immunological studies were carried out, Parinaud's syndrome in this case can be attributed to a remote effect of the lung cancer.