Leg length inequality is common. Treatment objectives include obtaining leg length equality, producing a level pelvis, and improving function. Clinical assessment should include determination of a level pelvis with the patient standing using a set of blocks of various heights to estimate the amount of leg length inequality. Radiographic measures include the teleroentgenogram, orthoradiograph, and computed tomography (CT). A prediction of the ultimate leg length inequality at skeletal maturity will be needed to determine treatment. Our guidelines for treatment of leg length inequality are as follows: <2 cm--no treatment or a lift in the shoe; 2 to 6 cm--an epiphysiodesis or shortening procedure is considered; 6 to 15 cm--a lengthening procedure is considered. A leg length inequality of 15 to 20 cm--may require a staged lengthening, lengthening combined with epiphysiodesis, or amputation. Numerous complications of limb lengthening procedures occur frequently, even in experienced hands.