This research extends longitudinally findings on child temperament as a moderator of the impact of socialization on conscience development, reported previously for contemporaneous data at toddler age. Children's temperament and maternal socialization at Time 1 (n = 103, aged 2-3 years) were considered predictors of future conscience, assessed using new observational and narrative measures. The moderation model was supported for predicting conscience at Time 2 (n = 99, age 4), and, to a lesser extent, at Time 3 (n = 90, age 5). For children fearful as toddlers, maternal gentle discipline, presumably capitalizing on the optimal level of anxious arousal, promoted conscience at Time 2. For children fearless as toddlers, perhaps insufficiently aroused by gentle discipline, alternative socialization mechanisms, presumably capitalizing on mother-child positive orientation (secure attachment, maternal responsiveness), promoted conscience at Times 2 and 3. Developmental interplay of temperament and socialization in emerging morality is discussed.