It is not an infrequent experience to see a subcutaneous hemorrhage in the eye-lid or conjunctiva localized not always ipsilaterally but sometimes contralaterally after an Oto-Rhino-Laryngological operation, especially after a sinus operation.In order to eludidate the cause of the hemorrhage, the author performed the following experimental study on the rat: croton oil was injected into the tissue of the wall of the paranasal sinus or into the buccal mucosa through the lip. Ipsi- or contralateraly located palpebral hemorrhage was obeerved to occur following the injection.Histological study of the palpebral tissue revealed that the lesion was mainly due to the vascular disturbance with edema, vaso-dilatation, stagnation of blood cells and hemorrhage, as well as localized necrosis in severly damaged areas.Lesions were also found in the lungs, liver, kidneys and other organs. Suzuki. Iida and Fukazawa described similar lesions due to vascular disturbance in those organs of the pig produced as a manifestation of the Reilly's phenomenon.In the author's experiment, intensity of the palpebral hemorrhage and of the lesions in those organs pararelled with each other.These facts has induced the author to interprete the hemorrgagic lesion in the eye-lid as a manifestation of the Reilly's phenomenon.