Symptomatology and pathogenesis of porphyria cutanea tarda (PCT) are shortly reviewed. The different possibilities in the treatment of PCT are discussed with special reference to the phlebotomy according to Ippen and to the chloroquine administration according to the regimen described by Kordac and Semradova in 1974. 75 PCT patients were treated with chloroquine (Resochin®, Nivaquine®). After 9.3 ± 3.4 months (means ± SE) all patients excreted normal amounts of porphyrins, and the clinical symptoms disappeared. 14 of these patients relapsed after a mean period of 21 months after the withdrawal of chloroqu