This article examines the effects of living arrangements on the well-being of mothers with a serious mental illness. Analyses of data from a National Institute of Mental Health-funded study of an urban, primarily African American sample of 379 mothers with mental illness revealed few differences in parenting or social functioning between mothers living with their children and a spouse or partner and those living with their children only. However, mothers living with their children and extended family had significantly better outcomes than women in the other two living arrangements. Structural equation modeling analyses indicated that living with relatives significantly related to mothers' well-being (social functioning and parenting) above and beyond relatives' provision of social support. Multilevel modeling revealed racial differences in the effects of living with relatives on functioning and parenting stress: Effects were positive for African American mothers but mixed for white American mothers.