The indications for skin expansion in the limbs are now well defined. This technique is particularly irreplaceable below the knee, and allows the resection of very large lesions despite a minimal skin capital. More than in other sites, it is a difficult technique which requires rigour and a sound basis in reconstructive surgery. The operative plan must include precise assessment of the tissue gain with selection of prostheses adapted to local conditions. The techniques of insertion, filling and resection must be irreproachable. The functional and aesthetic indications are numerous and the technique often provides a minimal residual scar.