Corrective measures on the bone undertaken after the fusion of epiphyses are only possible through an initial break in its continuity. This paper deals with the different methods of osteotomy available to the orthopaedic or trauma surgeon. After introducing the terminology of the so-called "osteotomy", the vascularity of the bone, special features of the various osteotomy site, the different indications, and particular details of the operative procedures are discussed. Special emphasis is placed on minimally invasive techniques and osteotomies in the framework of callus distraction. In addition to established procedures a new sawing technique for the Küntscher's closed osteotomy is described.