This study is a phase I, prospective, open-label trial designed to assess the safety of a single allogeneic sibling cord blood infusion in young children with cerebral palsy. Children ages one to six years with uncomplicated cerebral palsy and an available HLA matched or haploidentical, qualified, sibling cord blood unit will be eligible to participate. All participants will receive a single intravenous infusion of allogeneic sibling cord blood. All participants will have an initial clinical evaluation to verify the diagnosis of cerebral palsy and determine eligibility. The main endpoint is safety, for which acute infusion reactions as well as incidence of infections and graft versus host disease will be assessed. Functional outcome measures, described below, will be assessed at baseline and six months post sibling cord blood infusion and described.