Continuous passive slow motion (CPSM) was used to aid postoperative rehabilitation in seven difficult pediatric knee and elbow problems. Four patients had joint erosion secondary to hemophilic arthropathy and three patients had joint irregularities associated with long-standing limitation of joint movement. CPSM was started soon after surgery at the slow speed of 1 revolution every 12.5 min. The early, slow mobilization did not cause pain and established an arc of joint motion before intraarticular adhesions became a problem. Compared with a similar group not using CPSM, our hemophilia patients did not require postoperative manipulation, had decreased hospitalization time, and gained a greater range of motion. The group with long-standing limited joint mobility exhibited maintenance and in most cases improved motion after surgery. Thus CPSM after surgery enhances the rehabilitation process of difficult pediatric knee and elbow problems.