Thirty-six percent of the runaway and homeless youth who come to shelters have experienced physical and sexual abuse in their families; 44 percent have been exposed to other long-term family crises such as drug-abusing, alcoholic parents or stepfamily crises; and 20 percent have had to deal with short-term crises such as divorce, sickness, death, and school problems. Most are ill-equipped to obtain jobs with a living wage, so they become prostitutes, which exposes them to multiple sex partners. Many know about acquired immune deficiency syndrome (AIDS), but they do little to reduce their likelihood of catching it. Their intravenous drug use and the injection of hormones exposes them to another means by which AIDS is transmitted. Among a small sample of kids tested for the AIDS antibodies at Covenant House, 27 percent tested positive, and more and more of the kids seen on the streets are sick, and their illnesses seem clinically related to AIDS. Obstacles to prevention and treatment make it likely that runaway and homeless adolescents will become a major segment of the population that contracts and transmits AIDS.