Prosocial lies—lies that are intended to benefit others—are ubiquitous. This article reviews recent research on the causes and consequences of prosocial lies. Prosocial lies are often motivated by the desire to spare others from emotional harm. Therefore, prosocial lies are frequently told in situations in which honesty would cause heightened emotional harm (e.g. when a target is fragile) and by people who are sensitive to others’ emotional suffering (e.g. those high in compassion). However, targets only react positively to prosocial lies when they prevent emotional harm and when honesty lacks instrumental value (i.e. when they prevent unnecessary harm). Outside of these situations, targets typically view prosocial lies as paternalistic and therefore penalize those who tell them.