A defect was created in the articular cartilage of the rabbit knee leaving the subchondral bone intact. The lesion was repaired by an autologous graft of costal perichondrium and fixed with fibrin glue. The result was compared with a nontreated defect in the contralateral knee. In 26 out of 30 knees, graft fixation proved to be adequate. In the grafted group the perichondrium developed macroscopically and histologically into normal hyaline cartilage. The nongrafted defects showed only limited repair.