The term "vascular" refers to the body's network of blood vessels. Vascular lasers target malformed blood vessels that can leave discolored marks on the skin. The lasers target the red color in blood and transmit a focused beam of light on blood vessels, heating and destroying selected vessels.

Vascular laser therapy can reduce the red-blue appearance of spider veins, for example, by intentionally forcing the affected vessels to clot. Most vascular lasers emit a wavelength of 500 to 1064 nm, the range which is required to penetrate the reddish cells. One such laser is the pulsed dye laser (PDL), which was introduced in 1989 with a wavelength of 585 to 595 nm.

Other vascular lasers/light sources, from shortest to longest wavelengths, include the intense pulsed light (500-1200 nm), the potassium titanyl phosphate (simplified as KTP) laser (532 nm), diodes (940 nm), and the neodymium-doped yttrium aluminum garnet (simplified as Nd:YAG) laser (1064 nm).