Public-private partnerships (PPP) have been advanced as a new tool of global governance, which can supply both effective and legitimate governance. In the context of recent debates on the democratic legitimacy of transnational governance, this paper focuses on accountability as a central component of legitimacy. The aim of this paper is to map transnational climate partnerships and evaluate their accountability record in terms of transparency, monitoring mechanisms and representation of stakeholders. Three types of partnerships are identified with respect to their degree of public-private interaction: public-private (hybrid), governmental and private-private. Most of the climate partnerships have functions of advocacy, service provision and implementation. None are standard setting, which indicates that governmental actors are less willing to “contract out” rule-setting authority to private actors in the climate change. Some partnerships, such as the World Summit on Sustainable Development climate partnerships and Clean Development Mechanism (CDM) projects represent “new” modes of hybrid governance with high degree of public-private interaction. However, many partnerships, not least the voluntary technology agreements such as the APP, rest on “old” form of governance based on the logic of lobbying, corporatism, co-optation and interstate bargaining. Private (business-to business) climate partnerships are to varying degrees geared toward quantitative targets in the Kyoto Protocol. The accountability record is higher for hybrid climate partnerships, such as the CDM, due to extensive reporting and monitoring mechanisms, while lower for the governmental networks, such as voluntary technology agreements. Partnerships do not necessarily replace or erode the authority of sovereign states, but rather propels the hybridization and transformation of authority that is increasingly shared between state and nonstate actors.