The development of fear, anger, and joy was examined in 112 children using a longitudinal design. Children were observed at 9, 14, 22, and 33 months in standard laboratory episodes designed to elicit fear, anger, or joy. At 14 months, mother–child attachment was assessed in the Strange Situation. The attachment groups (avoidant, secure, resistant, and disorganized/unclassifiable) differed in the trajectories of emotional development, with the differences first apparent at 14 months of age. Resistant children were the most fearful and least joyful, and fear was their strongest emotion. More than secure children, they responded with distress even in episodes designed to elicit joy. When examined longitudinally, over the second and third years, secure children became significantly less angry. In contrast, insecure children's negative emotions increased: Avoidant children became more fearful, resistant children became less joyful, and disorganized/unclassifiable children became more angry. Higher attachment security uniquely predicted that at 33 months, children would show less fear and anger in episodes designed to elicit fear and anger, and less distress in episodes designed to elicit joy, even in conservative regression analyses controlling for all the earlier emotion scores.