Among the most vulnerable of persons without a safe and dependable place to call home are those who have not yet reached physical or emotional maturity.The following articles focus on mental and behavioral health issues for homeless children and youth living with one parent or none - doubled up with relatives or friends, in emergency shelters, in foster care or group homes, or on the street. A brief review of the recent literature summaries mental health risks and service needs of homeless minors and young adults, and highlights recommended strategies to prevent the developmental delays and major behavioral problems that are associated with prolonged homelessness. Eight homeless service providers discuss the challenges they face in working to protect the mental health of growing numbers of rootless young people in Daly City, California; Seattle, Washington; San Antonio, Texas; Chicago, Illinois; Cleveland, Ohio; and Baltimore, Maryland.