The Author reports on the simultaneous appearance of a skin manifestation of the B.B.S. disease in female Twins. Partly diffuse and partly nodose infiltrations, with tendency to peripheral extension and central resolution constituted the clinical picture of the disease: (diffuse, small nodose variety of Boeck's sarcoids). In both cases the localisation was on the right cheek, the time-course was very similar. The histological picture was almost identical and was represented by infiltrations of epiteloid-cells with concentrical distribution.