Natural sunlight’s beneficial effect on psoriasis has been long known. This observation led over the past century to the utilization of artificial light sources for the treatment of psoriasis. For over seven decades, phototherapy using artificial ultraviolet light has been an established standard in the treatment of psoriasis. Advancements in our understanding of ultraviolet energy and photobiology have led to a number of available modalities in this field. After a brief historical introduction, we will discuss these techniques in detail, with emphasis on indications, efficacy, advantages and disadvantages and administration of each modality.