To design diagnostic criteria for reflex sympathetic dystrophy (RSD) and to initiate a prospective treatment protocol, we reviewed our experience with 49 episodes of RSD in 36 children. There were 24 females and 12 males; mean age at diagnosis was 13.4 years (range: 8 to 19); mean time from pain onset to correct diagnosis was 9.2 months (range: 1 to 53). Lower extremity involvement predominated. Pain was "severe" in 61%, and skin color changes, swelling, hyperesthesia, abnormal skin temperatures, muscle weakness, and decreased range of motion were all present in at least 75% of cases. Osteopenia was observed in 15 of 38 radiographs; of 24 bone scans, 7 were normal, 11 showed increased uptake, and 6 demonstrated decreased uptake. Of the 23 children who had psychological evaluations, 83% revealed some type of significant emotional dysfunction. Analgesic and antiinflammatory medications were not helpful, nor were local injections or regional blockades effective. An inpatient diagnostic and rehabilitation program for treating chronic pain, including orthopedics, rheumatology, psychology, and twice-daily physical therapy was most likely to lead to resumption of age-appropriate activities. Despite extensive physiological testing, physician, parent, and/or patient reluctance to accept absence of a primary organic disease was common. We present diagnostic criteria for pediatric RSD.