The international treaties for the protection of the ozone layer and the global climate are closely related. Not only has the Montreal Protocol for the protection of the ozone layer served as a useful example in developing the international climate regime, but policies pursued in both issue areas influence each other. This paper gives an overview of the many ways in which both treaty systems are linked functionally and politically. It investigates, in particular, the tension that has arisen with respect to the use of fluorinated greenhouse gases and the potential for drawing on the experience under the Montreal Protocol regarding data reporting and policy design on fluorinated greenhouse gases under the Kyoto Protocol to the United Nations Framework Convention on Climate Change. The potentials for enhancing synergy in these areas are explored, and related options discussed. Some initiatives for exploiting these potentials are already underway, aiming in particular at enhancing learning and exchanging of information. However, political choices concerning some of the issues will eventually need to be made, if action at the international level is to contribute to their solution.