Objective: The study aimed to investigate the possible relationship between maternal psychological state in the perinatal period and the child’s temperament at 3 months postpartum. Background: The perinatal period is a phase of intense psychological complexity which may increase the risk of the development, or a recurrence of psychological disturbances in parents. The current literature highlights the potential negative effects of a perturbed maternal psychological state on fetal and newborn development. Among the consequences of fetal exposure to maternal states of depression or anxiety are increased inconsolable crying and sleep disturbance in the newborn, difficult temperament, motor and cognitive development delays in children and a higher risk of depression in adolescence. Methods: A longitudinal design using self-report measures of maternal mood, and maternal report of the infant’s temperament, was used. The sample comprised 107 Italian, low-risk nulliparous women. Maternal and infant variables were assessed in the third trimester of pregnancy and at 3 months postpartum. The variables measured included: maternal depression, anxiety, prenatal attachment, alexithymia, social support, maternal bonding with parents, stressful events, and the infant’s temperament. Results: Higher scores of antenatal depression and postnatal state anxiety were independent predictors of increased temperamental difficulties of the baby. Conclusion: The results support the hypothesis that maternal perinatal states of depression or anxiety are associated with increased difficulty in the temperament of the baby as perceived by mothers. This therefore supports the need for prevention-treatment programmes from the early stages of pregnancy. © 2014, © 2014 Society for Reproductive and Infant Psychology