This research examines domestic and oversea's barrier-free design guidelines provided exclusively for children and their implementations in the common spaces of the outpatient clinics in two pediatric rehabilitation hospitals in Seoul. Based on literature review, a checklist was developed to compare various barrier-free design guidelines in consideration of children's accessibility in space. In addition, four spatial areas in the outpatient clinics of the two hospitals were investigated based on the checklist. As a result, the domestic and Japanese guidelines were aiming primarily to all user groups regardless of ages. Whereas in other oversea's guidelines, a number of barrier-free design standards exclusive for children were found in the facility items such as handrail, sink, urine, toilet, water fountain, chair, table, shelve, and so on, throughout the indoor waiting and sanitary spaces. Concerning implementations, most of the items in the indoor passage, waiting, and sanitary spaces of the two hospitals were not sufficiently facilitated enough to meet with the barrier-free design standards exclusive for children. As such, it is recommended to review and improve the current domestic barrier-free design guideline to accommodate various physical and spatial needs of children in all age groups and regardless of disability types, in the design of a pediatric rehabilitation hospital in the future.