The authors identify risk and protective factors for family homelessness, in a case-control study of homeless and low-income, never homeless families, all female-headed. Homeless mothers were enrolled from family shelters in Worchester, MA. Low-income housed mothers receiving welfare formed the comparison group. The women completed an interview covering socioeconomic, social support, victimization, mental health, substance use, and health domains. Childhood predictors of family homelessness included foster care placement and the respondent's mother's use of drugs. Independent risk factors in adulthood included minority status, recent move to Worchester, recent eviction, interpersonal conflict, frequent alcohol or heroin use, and recent hospitalization for a mental health problem. Protective factors included being a primary tenant, receiving cash assistance or a housing subsidy, graduating from high school, and having a larger social network. The authors conclude that factors that compromise an individual's economic and social resources are associated with greater risk of losing one's home (authors).