A study of limb lengthening by distraction epiphysiolysis in the rabbit tibia is presented. For this purpose a special external distraction device was developed, which allowed 10 mm lengthening of the leg. Bone formation in the distraction zone was quantified by means of computed tomography. Cross-sectional scan planes at 1.5 mm separation revealed bone formation proceeding for several weeks after the end of the distraction period. A period of bone remodeling followed, resulting in the formation of a solid cortical structure, similar to the diaphysis, in the distraction zone.