The study examined whether preschool children conceive of empathy-based comforting as being an obligatory reaction toward others in emotional need. We presented 3- and 5-year-old children with three scenarios in which protagonists showed different reactions toward an agent who has hurt herself. One protagonist reacted antisocially by laughing at the agent, one ignored the agent, and one demonstrated empathy-based comforting. The 3-year-olds only protested against the antisocial protagonist. In contrast, the 5-year-olds protested against the protagonists who either acted antisocially or ignored the needy other while they selectively affirmed the protagonist who showed empathy-based comforting. The findings indicate that a norm for empathy-based comforting develops in the preschool years. Overall, our study demonstrates the emergence of a normative concern with the well-being of others, a central aspect of human altruism.