The mandibular condyles of eight growing male monkeys (Macaca fascicularis) were analyzed by using a combination of radioautographic and morphometric techniques. This was done with the aim of examining the dynamics in the structure and growth activities of the articular tissue covering as well as of the subchondral zone of erosion. The animals received 1 mCi/kg body weight 3H-proline 24 hr and 0.5 mCi/kg body weight 3H-thymidine 3 hr prior to death. Their age was estimated on the basis of skeletal maturation as recorded from radiographs of the hand and wrist. Consistently, the proliferative activity in the intermediate layer, the rates of cell turnover and growth of chondroblasts and chondrocytes, the rates of extracellular matrix production in the intermediate and chondral layers, as well as the resorptive and appositional activities in the zone of erosion were characterized by an in-concert behavior. This behavior suggests a general synergistic control of the various cell dynamic and metabolic processes affecting the rate of normal condylar growth.