This article begins by focusing on the development of conference diplomacy during the long nineteenth century. It then describes how global problems gave rise to global conferences, which begin to constitute a new element in the UN system. This is followed by discussions of the process of conference diplomacy and Gilbert Winham’s insights on negotiations. Conference diplomacy emerged from the pursuit of state interests by the great powers, in particular, in an international setting. This framework was largely predominant until 1970, but thereafter there has been a change of tone, whereby conference diplomacy has been much more concerned with the search for common interests in a multilateral and multilevel setting. The reason for this is primarily the growth of global problems, which are exacerbated by the process of globalization. In turn, global conferences have extended the UN system not only to enfranchise new actors, but also to take a fresh look at old problems.