Prosocial behaviours appear very early in a child's development, suggesting that they are the basis for building social relationships. Previous studies have shown that two main factors influence decisions about pro-social behaviour: in-group membership and reciprocity. The main aim of this study was to investigate which of these motives children consider more important in making decisions about who to ask for help, resources, cooperation, or comfort. Children were given a choice to ask for those favours from either a friend or an out-group child who was recently a recipient of the child's prosocial behaviour. In a study on children aged 4 to 6 years old with two research samples (sample 1: n = 60, sample 2: n = 71), we showed that reciprocity of recent prosocial behaviour is a stronger predictor than friendship when choosing a character in a helping need, resource sharing or cooperation related need, but not for a comforting need. Furthermore, this effect seems to be limited to reciprocating only the same type of pro-social behaviour.