AbstractOne of the first clinical uses of the laser was in dermatology. It was used to help in diagnosing not only the presence of disease but the extent. It was used in various large naevi and very soon in port wine stains and other vascular anomalies. Skin cancer soon was treated with the laser, and soon tumors in patients with various platelet defects could be resected successfully with a minimal risk. The advent of photodynamic therapy now allows successful treatment of many lesions.