This study focused on mothers' affective and behavioral responses to hypothetical displays of preschoolers' relational and physical aggression. We hypothesized that lower levels of negative affect and a lower likelihood of intervening in conflicts would occur for relational aggression than for physical aggression. We also expected significant differences in the qualities of mothers' proposed intervention strategies as a function of the form of aggression. 87 mothers of preschool children read hypothetical stories involving their child engaging in relational and physical aggression in preschool. 27 mothers also read stories depicting reactive and proactive displays of relational and physical aggression. Mothers reported their feelings and what they would do or say if they witnessed the events in each story. Results provided support for hypotheses and suggest that mothers hold different beliefs about relational versus physical aggression. Theoretical and practical implications of these findings are discussed in relation to current models of parental influences on children's social competence.