Parents and children often engage in joint play - a domain where mothers and fathers are thought to exhibit disparate behaviors and impact child development via distinct pathways. However, little is known about the neural substrates of mother-child and father-child play. In this fMRI study, we sampled brain activation of parents of pre-schoolers (N=88) during a novel event-related adaptation of the virtual ball-tossing game “Cyberball”. Mothers (N=40) and fathers (N=48) played “Cyberball” ostensibly with their own and an unrelated child, who consecutively included, excluded, and re-included parents. We found that overall, exclusion yielded comparable neural activation in mothers and fathers associated with mentalizing, saliency, and emotion-processing. We also observed a parent gender effect in several brain areas: While mothers exhibited increased reward- and attention-related activity during inclusion, fathers displayed increased mentalizing-related activity during exclusion. Additionally, we tested parents’ response to re-inclusion, which revealed a selective decrease in reward-related activity. There were no differences in parental brain activity as a function of child identity (own vs. unrelated). This study elucidates the common and distinct means by which mothers and fathers engage with their children, especially during play, lending support for theories postulating partial differentiation of paternal and maternal parenting systems.