The following report of the occurrence of sarcoidosis in two women who are identical twins presents some interesting observations in regard to the course of the disease in persons so related. REPORT OF CASES Case 1.— A white housewife, 24 years of age, was first seen at the Cleveland Clinic on Dec. 20, 1947. During the six weeks prior to her visit she had noted, in order of onset, swelling of the upper eyelids, painless swelling of the left side of the face, and, two weeks later, swelling of the right side of the face. She also experienced dryness of the mouth, fatigability, mild headache, and asthenia. Prior to the appearance of these symptoms she had enjoyed excellent health. Examination at Admission.— The temperature was 99.7 F, height 5 ft. (152 cm.), and weight 110 lb. (49 kg.). The parotid glands, particularly the left, were enlarged and slightly tender,