Objective: The available research on childhood exposure to intimate partner violence (IPV) tends to focus on the effects of exposure to IPV involving parents. The current study explores the prevalence of exposure to IPV involving adults other than parents. Method: College-age men (N = 483) retrospectively report on their childhood exposure to IPV involving parents and IPV involving other adults. Participants also report their own experiences with IPV as adults. Results: Approximately a quarter of participants report witnessing IPV in which parents are neither perpetrators nor victims. Participants commonly report witnessing IPV involving nonparent adults such as family friends, grandparents, uncles and aunts, adult siblings and their partners, and other relatives. In addition, childhood exposure to IPV between nonparents accounts for unique variance in later perpetration of IPV, over and above the effects of exposure to IPV involving parents. Conclusions: Findings suggest that childhood exposure to IPV involving nonparent adults is common. Results are preliminary, but suggest that IPV between nonparent adults may represent an understudied aspect of childhood exposure to IPV. (PsycINFO Database Record (c) 2015 APA, all rights reserved)