The Group of 77 developing countries (G77), which emerged as a coalition in the United Nations Conference on Trade and Development (UNCTAD) in 1964, has been a major force in the promotion of enlarged and improved international development policies. The main challenges posed by the G77 were aimed at integrating development within the scope of international economic organizations, including Bretton Woods institutions. This paper shows that UNCTAD’s advocacy shifted the International Monetary Fund’s (IMF) paradigm on stabilization policies by challenging the unicity of its approaches in developed and developing countries. IMF staff proved sensitive to developing countries’ economic issues raised by UNCTAD Secretariat and experts. UNCTAD also provided a political platform for G77 members to contest Western countries’ monopoly over monetary affairs. As negotiations on the reform of the international monetary system unfolded, G77 obtained two main concessions. First, the Fund modified its lending facilities. Second, developing countries were included in the 1969 reform of the IMF that created the Fund’s new reserve asset: the Special Drawing Rights (SDRs). Some currently resurfacing ideas such as the “link” between development financing and SDRs allocation were crafted in these debates. This paper offers new perspectives on both UNCTAD’s role in the monetary and financial fields, and on the part played by development to shape IMF policies.