This article examines the role of social networks and informal institutions in facilitating the resettlement and socio-economic integration of Vietnamese returnees from Cambodia in the Tri An Lake region, Dong Nai Province. In the context of statelessness and the absence of legal identification, these returnees faced significant barriers in accessing official support from local authorities. Under such circumstances, kinship-based networks, fellow migrant connections, and local community ties—together with informal support mechanisms —played a pivotal role in providing essential resources such as shelter, livelihood opportunities, informal credit, and emotional support. Drawing on oral history interviews with Vietnamese returnees who have resettled around Tri An Lake since the late 1980s, the study reveals that these social connections and informal institutions helped individuals navigate initial crises and contributed significantly to their long-term stability and integration.