Abstract. [Purpose] This study aimed to verify the effect of hippotherapy on the sitting balance of children with severe cerebral palsy (CP) by comparing hippotherapy, physical therapy, and a control. [Subjects] In this study, 45 children with CP were randomly divided into the hippotherapy group (HTG, n = 15), physical therapy group (PTG, n = 15), and control group (CON, n = 15).[Methods] Two expert physical therapists provided the HTG and PTG with traditional physical therapy comprising strengthening and stretching exercises in 30-minute sessions, semi-weekly, for 8 weeks . Hippotherapy was provided semi-weekly only to the HTG for 8 weeks at 30 minutes per session. The CON group received no treatment. Before and after the 8 weeks of intervention, a sitting balance test was performed, and the results were analyzed.[Results] Sway pathway and velocity significantly decreased in HTG compared to PTG and CON. Left/right pathway, total pathway, left/right velocity, and total velocity were significantly reduced in PTG compared to that in the CON.[Conclusion] Hippotherapy withtraditional physical therapy improved the sitting balance ofchildren with severe CP, who could not walk independently more than traditional physical therapy alone.