As more countries use HTA to inform decisions on the reimbursement of health technologies, harmonization of evidence requirements between jurisdictions has been proposed, mainly on the grounds of improved efficiency. Harmonization has the potential to avoid duplication of effort for both manufacturers and HTA bodies involved in preparing and reviewing HTA submissions for innovative technologies. However, it also carries risks of loss of local control over decisions, the application of general data standards which are not universally accepted and slowing the rate of development of innovation in the analytical disciplines supporting HTA. This study reviews the issues associated with harmonization taking into account the perspectives of the multiple stakeholders. This study draws on experiences from recent initiatives intended to promote the harmonization of HTA and experience from related fields, particularly regulatory approval of new medical technologies.