In discussing marriage negotiations, this article analyses certain mediations and mediators that make up the dialectics of modernisation among contemporary urban middle-class elites in Timor-Leste. It brings to the fore the way particular Christian values are strategically used to reproduce, change or even enhance people's agency regarding customary practices, and to circumscribe the marriage exchanges to the gift regime. Attitudes about fulfilling customary obligations vary, for they are correlated to the distinct government practices from which they derive. The social profile of brokers and the sources of their legitimacy to perform marriage negotiations are also discussed. Finally, these negotiations are analysed against the backdrop of contemporary arguments about the syncretic or anti-syncretic character of some social experiences in Timor-Leste.