This review covers the current practice of phototherapy with ultraviolet (UV) radiation without sensitizers and of psoralen photochemotherapy (PUVA) in the treatment of psoriasis. Both treatment modalities are well established in today's therapeutic armamentarium. Phototherapeutic regimens use repeated controlled UV exposures to alter cutaneous biology, aiming to induce remission of skin disease. Although UVB has been used for a longer time than PUVA, the latter has been evaluated and validated in a more detailed and coordinated fashion.