Unilateral condylectomy was performed on five young adult sheep. The animals were killed at three months and both joints and the excised condyles were examined macroscopically and histologically. All five showed pronounced regeneration of the condylar head on the operated side. The articular surface was fibrous and fused to the disc. Four of the five opposite joints showed medial remodelling. Young sheep have a higher regenerative capability than human adults of equivalent age, and similar reactions to those of children.