Fractures through the distal femoral epiphysis of rats were produced by applying a varus angulating force. This resulted in distraction on the lateral side of the epiphyseal plate and compression on the medial side. On the distraction side the fracture line passed through the zone of hypertrophic cartilage cells. On the compression side it either involved the metaphyseal bone or resulted in a grinding injury to deeper layers of epiphyseal cartilage cells. Three types of healing are described which are determined, apparently, by the level of the fracture within the epiphyseal plate.