Objective: Early temperamental characteristics may influence children’s developmental pathways and predict future psychopathology. However, the environmental context may also shape or interact with infant temperament and indirectly contribute to increased vulnerability to adverse developmental outcomes. The aim of the present study is to explore the long-term contribution of temperamental traits at twelve months of age to the presence of emotional and behavioral problems later in childhood, and whether this association varies with the child’s sex, parental separation, family socioeconomic status and maternal depression. Method: 1184 mother-child pairs from the EDEN mother-child birth cohort study based in France (2003 +/- 2011), were followed from 24 +/- 28 weeks of pregnancy to the child’s fifth birthday. Infant temperament at 12 months was assessed with the Emotionality Activity and Sociability (EAS) questionnaire and behavior at 5.5 years was assessed with the Strengths and Difficulties Questionnaire (SDQ). Results: Emotional temperament in infancy predicts children’s overall behavioral scores (beta = 1.16, p < 0.001), emotional difficulties (beta = 0.30, p < 0.001), conduct problems (beta = 0.51, p < 0.001) and symptoms of hyperactivity/inattention (beta = 0.31, p = 0.01) at 5.5 years. Infants' active temperament predicts later conduct problems (beta = 0.30, p = 0.02), while shyness predicts later emotional problems (beta = 0.22, p = 0.04). The association between the child's temperament in infancy and later behavior did not vary with children's own or family characteristics. Conclusion: An emotional temperament in infancy is associated with higher levels of emotional and behavioral difficulties at the age of 5.5 years. Children who show high emotionality early on may require early prevention and intervention efforts to divert possible adverse developmental pathways.