G-20 originally a grouping of Finance Ministers under the aegis of IMF was elevated to the summit level and used quite effectively during the global financial and economic crisis of 2008–2009. Starting from the Seoul summit, G-20 leaders sought to make a transition from responding to a contingent situation to deal with the structural problems of the world economy. These included the problems of development, IMF reforms, international reserve currency and financial regulation. G-20 summit deliberations since then have not led to any significant progress in any of these areas. Objectives and policy measures agreed upon in almost all major areas of concern to G-20 are platitudinous in nature, having little operational significance. Moreover, they are couched in terms which makes it impossible to hold any government accountable for success or failure. G-20 has a very tenuous legal justification to play the role assigned to it. A vast majority of the members of the United Nations are outside it. Besides, given the composition of the G-20, emerging economies like India, China, and Brazil cannot in any effective manner that influence the outcome of G-20 deliberations. G-20 represents a significant institutionalization of the ongoing process of the erosion of the economic functions of the United Nations. In view of the above, interests of India, Brazil and other emerging economies can be best served through cooperation within the United Nations. However, the G-20 in its new role is firmly established and is likely to remain active in the near future. Therefore, a principal challenge for countries like India is to seek to reconcile their role in the wider forums of the United Nations with that in the G-20.