International audience As a religious belief, cultural imaginary and social world, Islam long remained unknown to many South Pacific societies. In densely populated Melanesian archipelagos like Papua New Guinea, the Solomon Islands and Vanuatu, concentrated since their independence on constructing national identities firmly rooted in Christianity, the introduction of Islam should be studied as a specifically postcolonial phenomenon. After several decades of sovereignty, some of these countries have nonetheless felt the need to reassert that hegemony of Christianity could admit of no national competition. However, with an intensification of the cultural consequences of globalization and secularization, they are going through social upheavals which are coupled with a moral crisis among older Christian denominations, confronted by the growing success of neo-Evangelical and Pentecostal churches. Converting to Islam, in such a context, is a religious innovation of special interest for social sciences specialists, since it became involved, in these countries, in debates on politics of culture and identity. What is at stake in this issue is the ability of Islam to conform or not to past Melanesian experiences in indigenizing foreign cultural influences. The aim of this presentation is to question the reasons for the adherence encountered regionally by this new offer on the faith market in certain urban or rural contexts, when in other respects Islam has also been the object of real mistrust locally. In the light of useful materials from Vanuatu I will comment the role played by Islam in the region and suggest comparative viewpoints on the religious, cultural and political dynamics behind it.