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 <.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 <.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.