The purpose of this study was to examine adolescent's hostile attributions of mother's intent and emotional self-expectancies as contributors to expression of emotion between mothers and adolescents. Data were collected from 268 10- to 12-year-olds (133 girls, 135 boys) and their mothers. Each dyad was observed in a conversational activity that was coded for both partners' expressions of four discrete emotions: happiness, anger, sadness, and fear. Adolescents responded to hypothetical stories to assess their emotional expectancies and attributions. Regression analysis revealed that adolescents' hostile attributions and emotional expectancies made independent contributions to the expression of happiness and anger with their mother. Adolescents who interpreted their mother's hypothetical behavior as hostile, and who expected to feel less happiness and more anger in response to their mother's hypothetical behavior, expressed less happiness and more anger with their mother. The findings support the conceptual distinction between hostile attributions and emotional expectancies.