This study was designed to assess the effect of an 8-week plyometric-based hydro-kinesio therapy (Plyo-HKT) on pain, muscle strength, postural control, and functional performance in a convenience sample of children with hemophilic knee arthropathy (HKA). Forty-eight patients with HKA were randomly allocated to the Plyo-HKT group (n = 24, received the plyometric-based hydro-kinesio therapy program, twice/week, over 8 weeks) or the control group (n = 24, received standard exercise program). Both groups were assessed for pain, muscle strength, postural control, and functional performance pre and post-treatment.