Metabolic alkalinization as therapy for porphyria cutanea tarda is easily accomplished and is without complications. Eight of ten patients with porphyria cutanea tarda treated by his means improved, as evidenced by a return of skin findings toward normal, reversal of abnormal results of liver function tests, and decreased urinary excretion of uroporphyrins. Five of these ten patients also abstained from further use of alcohol during treatment, and all five improved in contrast to a lessened response in five patients who continued to use alcohol. Thus, omission of alcohol as a treatment factor in itself must be considered in any therapeutic program. Although the exact role of iron metabolism in the etiology of porphyria cutanea tarda is not known, hemodynamics in patients judged to be improved showed decreased values for serum iron, a change that is similar to the changes reported when patients with porphyria cutanea tarda are treated by repeated phlebotomies. The two patients in the series who did no improve showed increased values for serum iron.