Generalized pustular psoriasis which is originally described by von Zumbusch in 1910, is the most intense form of the acute exanthematic variant among psoriasis. It is to be occured as a rare disease and the familial occurrence rarely has been reported. Many therapeutic attempts have been rnade to bring the condition under control, but none has unequivocally proven to alter its courae decisively. We present two cases of generalized pustular psoriasis in brother and sister (16 year-old male, 19 year-old female) which were treated successfully by pbotochemotherapy (PUVA).