The high-risk sexual behavior called running a train appears similar but not necessarily identical to gang rape or fraternity rape. According to respondents, trains may be spontaneous or planned, take place at parties or in a variety of other settings, almost always involve alcohol and/or drugs, and the participation of the female is often perceived to be consensual by involved males. Results suggest that involvement in trains may place both male and female participants at increased risk for the transmission of sexual infections and may place females at risk for trauma, physical injury, and unintended pregnancy. Additional research is recommended of the public health consequences of this understudied high-risk sexual behavior among adolescents. Trains occur among adolescents in the United States, although documentation, study, and description of this phenomenon are lacking. With that said, it is not clear whether trains should be viewed and treated as gang rapes or another related but distinct sexual behavior. In 2005, a two-phase qualitative study to investigate the relationship between teen dating violence perpetration and sexual and reproductive health in the United States was conducted. This present study was designed to explore the context and implications of train-related behavior in order to generate testable hypotheses about associated sexual and reproductive health risks. In addition, it explores the extent to which the described behavior meets the criteria for rape and therefore whether it should be categorized as a form of sexual assault in the public and adolescent health literatures. Interviews were conducted with 25 adolescent males ages 14 to 22 on the topics of sexual behaviors and dating violence. Table, references