Nationally representative data indicate that adults in the United States are increasingly delaying the decision to have children or are forgoing parenthood entirely. Although some empirical research has examined the social consequences of adults’ decision to be childfree, few studies have identified explanatory mechanisms for the stigma this population experiences. Based on the logic of backlash theory and research on retributive justice, the present research examined moral outrage as a mechanism through which voluntarily childfree targets are perceived less favorably than are targets with children for violating the prescribed social role of parenthood. In a between-subjects experiment, 197 undergraduates (147 women, 49 men, 1 participant with missing gender data) from a large U.S. Midwestern urban university were randomly assigned to evaluate a male or female married target who had chosen to have zero or two children. Participants completed measures of the target’s perceived psychological fulfillment and their affective reactions to the target. Consistent with earlier studies, voluntarily childfree targets were perceived as significantly less psychologically fulfilled than targets with two children. Extending past research, voluntarily childfree targets elicited significantly greater moral outrage than did targets with two children. My findings were not qualified by targets’ gender. Moral outrage mediated the effect of target parenthood status on perceived fulfillment. Collectively, these findings offer the first known empirical evidence of perceptions of parenthood as a moral imperative.