Most research on adverse childhood experiences (ACEs) has been conducted in high-income countries in the global North. The current longitudinal study examined the prevalence, overlap, and impact of ACEs in a sample of Brazilian children and adolescents who use city streets as spaces for socialization and survival (i.e., street-involved youth). Participants (N = 113; M age = 14.18 years) were recruited in three cities following standardized procedures. Most youth were male (80.5%) and non-White (91%). Lifetime exposure to ACEs was assessed at the first study time point; six indicators of psychological, behavioral, and physical adjustment were assessed 6 months later. Analyses addressed three research goals. First, the prevalence of seven ACEs was examined. Youth reported an average of 4.8 ACEs (SD = 1.25); no significant age or gender differences were found in ACEs exposure (all ps >.05). Second, the overlap between different ACEs was explored. Family dysfunction was correlated with family disruption and physical abuse; poverty and physical abuse were related (ps less than .05). Third, prospective associations between ACEs and adjustment were tested. Total number of ACEs was not significantly correlated with any outcome, but several associations emerged for specific ACEs. For example, death of a close friend or family member was prospectively associated with negative affect; sexual abuse was associated with illicit drug use and physical health symptoms (ps less than .05). Findings highlight the prevalence of ACEs in this vulnerable population and underscore the value of extending research on ACEs into novel populations and contexts. © 2018 Elsevier Ltd