It is with some hesitation that I report a case of the jaw-winking phenomenon, since I know full well that it has little clinical value and that the condition is so rare as to be possibly unimportant. However, it is felt that the rarity and curiousness of the disorder are in themselves sufficient reason for bringing it to the attention of ophthalmologists. The condition which has been called, rather inelegantly, the jaw-winking phenomenon was first described by Marcus Gunn in 1883, when he showed a patient with this disorder before the Ophthalmological Society of the United Kingdom. Since that time about ninety additional cases have been reported, although there is some reason to question the authenticity of some of them. In 1895 Sinclair1 collected a number of instances and discussed several possibilities as to the etiology. Sym2 in 1908 reported a case and again reviewed the etiologic