Abstract: An understanding of harm is central to social and cognitive development, but harm largely has been conceptualized as physical damage or injury. Less research focuses on children’s judgments of harm to others’ internal well-being (emotional harms). We asked 5- to 10-year-old children (N = 456, 50% girls, 50% boys; primarily tested in Central New York, with socioeconomic diversity, but limited racial/ethnic or linguistic diversity) to compare emotional and physical harms. In Experiment 1, children compared simple harms (intended and completed) and then scenarios in which the perpetrator’s intention did not match the outcome (intended emotional harm, but caused physical harm, or vice-versa). Assessments of the severity of emotional (vs. physical) harm increased with age and depended on the perpetrator’s intentions. In Experiment 2, children saw emotional and physical harms that were: Simple (intended and completed); Incomplete (intended, but not completed); or Accidental (not intended, but completed). Children evaluated physical and emotional harms in isolation and then compared the two. Judgments of the relative severity of emotional harm increased with age, but only when intentions and outcomes were both present. This reflected an increase with age in children’s perceptions that emotional harm was hurtful, whereas perceptions of physical harm were relatively stable across development. With age, children also increasingly associated emotional harms with longer-term impacts (being remembered and reoccurring). These findings suggest reasoning about the severity, underlying intentions, and duration of emotional harm shifts with age. The results hold implications for moral development, law and psychology, and emotional-harm-related interventions including those addressing bullying.