The present study uses social network analyses to examine the associations between children's prosocial behaviour and classroom affiliative relationships (i.e., hanging out relationships). Our sample includes data from 257 children and their teachers in 12 s through fourth-grade classrooms living in high-poverty, inner-urban city neighbourhoods (98.4% African American). We estimated a series of exponential random graph models (ERGMs) for the 12 classrooms and then meta-analysed the ERGM results using a multi-level meta-analysis technique to examine the effects of prosocial behaviour and homophily of prosocial behaviour on children's affiliative relationships across classrooms. Our results revealed a significant effect of prosocial behaviour, suggesting that children with higher levels of prosocial behaviour were more likely to have more affiliative relationships. We also saw a significant effect of homophily of prosocial behaviour, suggesting that the more similar the children were in terms of prosocial behaviour, the more likely they were to have an affiliative relationship. Our findings highlight the importance of prosocial behaviour in children's affiliative relationships and have implications for fostering children's affiliative relationships and improving their well-being.