Background: Biological vulnerability at birth increases the risk for poor development across the life-course. However, a small number of these vulnerable infants show normative development. What characterises these infants is, as of yet, unknown. In order to shed light on this issue, the current study aimed at investigating developmental resilience among infants with a biological vulnerability, and to see whether temperament, breast feeding, and pacifier use moderated this relationship. Method: A sub-sample (31127 births) within the Norwegian Mother and Child Longitudinal Cohort Study (MoBa) was selected based on the completion of items included in the study. Biological risk was defined as one or more of the following: low birthweight, birth complications, low Apgar score 5 minutes after birth, unplanned caesarean and being referred to a specialist. Developmental resilience was defined as above average development at 6 months, using items adapted from the Ages & Stages Questionnaire (ASQ). Results: A cumulative effect of risk was found, the less biologically vulnerable the infant were the higher the odds of showing developmental resilience. What promoted developmental resilience differed for low risk and high risk infants. For low risk infants, having an easy temperament such as being easy to sooth and to seldom cry was associated with developmental resilience. For high risk infants, however, being breast fed was associated with developmental resilience. Pacifier use at bedtime was associated with developmental resilience for females only. These findings were still present after controlling for mother’s age and the parents level of education and income. Conclusion: The moderating role of temperament, breast feeding and pacifier use on infants being biologically vulnerable and their development, depends on the degree of biological risk and, to a lesser extent, gender.