Sexual risk behaviors, knowledge of acquired immunodeficiency syndrome (AIDS), and beliefs about AIDS prevention were examined among 126 runaways. In the previous 3 months, 65 percent of youths had been sexually active. Among the sexually active runaways, males reported a median of 2.7 partners and females reported 1.3 partners, and only 18 percent reported consistent condom use. Runaways demonstrated moderately high AIDS knowledge and beliefs endorsing AIDS prevention. Condom use and abstinence were directly related to beliefs about preventing AIDS.