The CO2 laser (10600nm) targets water. Its affinity for water is inferior to that of the Er:YAG laser and therefore when it impacts the skin, it not only removes it but it also releases a modest amount of heat. This heat causes the collagen fibres in the dermis to contract and, above all, it stimulates the fibroblasts to produce new collagen. CO2 lasers can be ultrapulsed, superpulsed, pulsed or continuous wave. When used without a scanner and with a very small focal point, they can cut the skin and at the same time coagulate the small blood vessels. A CO2 laser with a scanner can be used to directly remove benign cutaneous neoformations (e.g. Keratosis, actinic or seborrheic), to even out the base of small cutaneous removals done with a scalpel (e.g. removal of facial nevi of Miescher), and to remove large and ample quantities of skin (e.g. Rinophyma correction). CO2 lasers also enable skin resurfacing, including fractional, for treatment of facial aging or acne scarring.