• All over the world, youth help others prosocially, in the context of their daily lives, communities, and cultures. • 82% of children live in low-and-middle-income countries, but most research is from privileged high-income-country samples. • This paper responds to recent calls to highlight the experiences of children from minoritized racial and ethnic groups. • Systemic inequalities–both within high-income countries and between hemispheres–confound current prosocial research. • We specify a research agenda to advance the understanding of prosocial development across communities worldwide.. Across psychology, there is increasing recognition that the experiences of children from minoritized racial and ethnic groups are underrepresented. Research on prosocial behavior exemplifies this systemic bias. This paper suggests that measures of prosocial behavior should be revised to be more culturally equitable, in order to reflect the experiences of youth across diverse communities. First, the authors briefly review literature on prosocial development in high-income countries. The authors advocate for revising measures to capture greater variability in the experiences of children from marginalized groups, and interpreting research findings in the context of systemic inequalities. Next, the authors review research on prosocial behavior in low- and middle-income countries (LMICs), which is limited but growing, and discuss next steps for future research on prosocial behavior in LMICs. The goal is to provide a specific research agenda to advance the understanding of prosocial development across contexts and communities worldwide.