Psoriasis vulgaris is a chronic disease in which demarcated erythema and rashes with silvery-white scales occur at various sites, and it is sometimes intractable. We report that Kampo medicines are effective in the treatment of psoriasis vulgaris. An 83-year-old woman suffered from erythema with pruritus and strong redness on the trunk and upper limbs and she visited the dermatology department. She was diagnosed with psoriasis vulgaris and started treatment with betamethasone ointment. However, her symptoms did not improved, and she requested Kampo medicine treatment. After the administration of maorenshoshakushozuto, erythema gradually improved. Maorenshoshakushozuto is effective for the dermatological diseases with pruritus and strong redness like psoriasis vulgaris.