The course of the recovery from the unfavourable effects of a rigid internal fixation plate on the strength of diaphyseal bone, measured as the maximum torque capacity, has been studied in rabbit tibiae. Due attention was paid to the screw holes. On removal of the plate, which had been applied for 12 weeks without prior osteotomy, the bone had decreased in strength by approximately 50 per cent. Following removal of the plate, the bone regained its normal strength after only 6 weeks. The regaining of strength proceeded in a significantly non-linear manner and in accordance with the logistic function: Formula: (See Text).