The laser has now become the staple tool of cosmetic medicine. It allows several treatments of the skin rapidly and without complication. The word ‘laser’, which became a common noun, is an acronym signifying ‘Ligth Amplification Stimulated Emission of Radiation’. In other terms, we use a light concentrate. The laser rays go through the skin without damaging it, to reach a precise target which will have a therapeutic effect. Lasers are used to : -Eliminate cutaneous unsightliness (redness, scars…). -Treat or slow down the signs of cutaneous aging (wrinkles, dermic densification). -Enhance daily comfort (laser hair removal). -Treat dermatologic lesions (laser in dermatology).