This study analyzed data from treatments of 385 cases of generalized pustular psoriasis (GPP) from 325 hospitals in Japan. Retinoid treatment was effective in 84.1% of patients, methotrexate in 76.2%, cyclosporine in 71.2%, oral PUVA therapy in 45.7%, and tonsillectomy in 16.7%. Short-term therapy with systemic corticosteroid for GPP during only the phase with severe systemic clinical findings may be also effective (75.4%). However, these treatments for GPP each differed in clinical effects, prognosis, and side effects. These findings may be useful in creating guidelines for treatment of generalized pustular psoriasis. Further studies based on these specific clinical effects are necessary.