What Kind of Laser Treatment Removes Dark Spots on Legs?

Dark spots are the result of excess melanin production in a concentrated area. Some birthmarks are caused by high skin pigmentation. And other forms of dark spots (e.g. age/sun spots) occur when the skin produces higher levels of melanin in response to sun exposure. This is how it tries to protect itself since melanin is like a type of sunscreen that your body manufactures. Fraxel Dual uses the 1550nm/1927nm wavelengths to break up this pigment in specific areas without being absorbed... more

Photos would help here! It's hard to say which laser is best without knowing what type of "brown spots" you are describing. IPL would be the most general answer, but it depends again, on what type of brown spots they are.