This study explores the interconnection that exists between loneliness and conflict structures in older adults' family networks. Research has shown that close family dyads, such as marriages or partnerships, often generate conflict, with negative consequences for mental health. However, such dyads are embedded in larger family networks with their own conflict structures. When considering the development of loneliness, the significant role of these larger conflict structures and their characteristics (i.e., density, centralization) has been disregarded, to a large extent, thus far. This research draws on the Vivre/Leben/Vivere survey, which investigated the family life and health conditions of people aged 65 and over living in Switzerland. Analyses focused on 890 individuals who participated in two waves of the survey, separated by 6 years. Regression and mediation models show that the conflict density of family networks is related to loneliness through its association with stress. The importance of network conflict structures is discussed.