Familismo has been described as a core cultural value for Latinos, but there have been few studies of its attitudinal and behavioral manifestations. We explored attitudinal and behavioral familismo using qualitative data collected from 23 Latina mothers who participated in an ethnographic study. The study employed semistructured interviews and participant observation methods carried out across 10 to 12 home visits for each participant. Results indicate that behavioral familismo manifests in five specific areas—financial support, shared daily activities, shared living, shared childrearing, and immigration—and functions as a dynamic construct that moves along a continuum of costs and benefits, over time and across situations, with implications for children’s development. The discussion highlights familismo as both a risk and protective factor for low-income, urban Latino families and underscores the importance of considering the balance between its costs and benefits in studies of Latino child development.