While parental monitoring is understood to protect adolescents from engaging in risk behaviors, little is known about how the family dynamics involved in parental monitoring differ across sociocultural contexts. We sought to gain an in-depth understanding of parent–child relationship dynamics and parental knowledge of adolescents’ activities in an urban Peruvian neighborhood with high levels of crime and adolescent substance use. We conducted 15 in-depth interviews and two focus groups with adolescents and 12 in-depth interviews with mothers sampled from a secondary school in Callao, Peru. Our findings emphasize the importance of parent–child confianza (trust) as a foundation for parental awareness of adolescents’ lives and activities. Participants in our sample characterized confianza as encouraging adolescent disclosure and shaping how parental solicitation and rules were interpreted by adolescents. Participants described how confianza was rooted in features of the parent–child relationship, including shared parent–child time, parental affection, adolescent perceptions of parents’ ability to give good advice, and awareness of how parents would react to delicate topics. Participants linked these family dynamics, in turn, to economic hardship, parental feelings of sacrifice and stress, perceptions of neighborhood risk, and gender norms limiting fathers’ involvement in caregiving. Results have implications for the planning and adaptation of family-based prevention programs for use in high-risk contexts in Latin America.