Generalized pustular psoriasis (GPP) is one of the neutrophilic dermatoses mainly caused by activated neutrophils and monocytes. Granulocyte and monocyte adsorption apheresis (GCAP) is a useful extracorporeal circulation therapy for removal of activated granulocytes and monocytes. In this study, GCAP was used to treat three patients with different types of GPP; the diagnoses indicated patient 1 had GPP, patient 2 had GPP developed from psoriasis vulgaris and patient 3 had GPP based on psoriatic erythroderma. We performed GCAP on each of these patients once a week, for a total of five times. We found that the patients' pustules and edema disappeared and their erythema was reduced by GCAP therapy. Moreover, no adverse effects were observed. Thus, we conclude GCAP could be effective for treating various types of GPP.