Background & Purpose—Given the extensive literature on body weight supported treadmill training (BWSTT) in adult rehabilitation, a systematic review was undertaken to explore the strength, quality and conclusiveness of the scientific evidence supporting the use of treadmill training and body weight support in those with pediatric motor disabilities. A secondary goal was to ascertain whether sufficient protocol guidelines for BWSTT are as yet available to guide pediatric physical therapy practice. Methods—The database search included MEDLINE, EMBASE, CINAHL Plus (Cumulative Index to Nursing and Allied Health Literature), PEDro (Physiotherapy Evidence Database), Cochrane Library databases, and ERIC (Education Resources Information Center) from January 1, 1980 until May 31, 2008 for all articles that included treadmill training and body weight support alone or in combination for individuals under 21 years of age, with or at risk for having a motor disability. We identified 277 unique articles from which 29 met all inclusion criteria Results—Efficacy of treadmill training in accelerating walking development in Down syndrome has been well-demonstrated. Evidence supporting the efficacy or effectiveness of BWSTT in pediatric practice for improving gait impairments and level of activity and participation in those with cerebral palsy, spinal cord injuries, and other central nervous system disorders remains insufficient even though many studies noted positive, yet small, effects. Increased use of randomized designs, studies with treadmill training only groups, and dosage studies are needed before practice guidelines can be formulated. Neural changes in response to training warrant greater exploration, especially given the capacity for change in developing nervous systems. Discussion and Conclusion—Large scale controlled trials are critically needed to support the use of BWSTT in specific pediatric patient sub-groups and to define optimal protocol parameters.