This paper draws on qualitative research in Jiwaka Province, in the highlands of Papua New Guinea (PNG), to examine the changing nature of marriage in that context. In particular, it examines how changes in the practice of brideprice have been associated with an increase in intimate partner violence. Violence, a relational process, is to be understood in the context of the customary unequal power relations between men and women. It is argued that men in the highlands of PNG see any gain in power for women as a loss for themselves, and so actively resist it. Men who see their power over women challenged resort to the discourse of brideprice, arguing that the payment of brideprice gives them absolute authority over wives. A good understanding of the norms that sanction violence is a vital step in developing interventions to prevent violence.