This paper provides a brief overview of the development of the Global Environment Facility (GEF) since its creation in June 1991 and the nature of its activities in the field of International Waters. Whilst it is recognised that the GEF represents the single largest source of international financial assistance for achieving global environmental benefits its investment in International Waters remains comparatively small. Since the GEF is designed to achieve global environmental benefits through provision of grant and concessionary funding for the agreed incremental costs of projects its primary objective is not capacity building. Nevertheless, the need for capacity building at the individual and institutional levels within projects was recognised early during the initiation of GEF activities. More recently the need for programmatic approaches to capacity building within the GEF has been identified and is being addressed. It is suggested that potentially the role of the GEF in environmental and marine capacity building could be most important at a global, system-wide level, in terms of testing and promoting innovative and novel approaches to issues of environmentally sound and sustainable economic development.