Developmental trajectories of infant nighttime awakenings are associated with infant-mother and infant-father attachment security

•Infants showed a non-linear decline in number and duration of infant nighttime awakenings over time.•Longer infant nighttime awakenings at 3 months were predictive of lower infant-mother attachment security at 24 months.•A higher number of infant nighttime awakenings at 3 months were associated with higher infant-father attachment security at 24 months.•A longer duration of infant nighttime awakenings at 3 months were associated with higher infant-father attachment security at 24 months.•Post-hoc analyses indicated no associations between paternal involvement in nighttime caregiving and infant-father attachment security.