Background: Parenting stress is influenced by many factors including maternal attachment and excessive infant crying, yet the nature of these relationships is not well understood. For example, excessive infant crying despite maternal soothing may impact maternal attachment to the child, leading to higher stress. This paper explored whether maternal perception of excessive infant crying at 6 months was associated with higher maternal parenting stress at 24 months, and whether maternal attachment mediated this relationship.Methods: All families, present at 24 months in a randomized controlled trial of a 5year early intervention programme targeting school readiness skills in disadvantaged area of Ireland, were included. At 6 months, infant crying was assessed using a maternal reported measure of duration of infant crying, and maternal attachment to the infant was assessed using the Condon Maternal Attachment Scale. Parenting stress was assessed at 24 months using the childrearing stress subscale from the Parenting Stress Index. Structural equation modelling was used to explore the direct and indirect effects of maternal perceptions of excessive infant crying on parenting stress, controlling for infant, maternal, and environmental characteristics, and focusing on the mediating role of maternal attachment.Results: Reporting excessive infant crying at 6 months was associated with lower maternal attachment at 6 months, which led to higher parenting stress at 24 months.In addition, vulnerable adult attachment style, previous maternal mental health difficulties, low paternal education, paternal involvement with the child, and not being married were associated with higher parenting stress.Conclusion: Findings suggest that the association between maternal perceptions of excessive crying at 6 months and later parenting stress may be mediated through maternal attachment to the infant. Interventions based on improving maternal attachment could be investigated to determine the effectiveness of supporting mothers with low attachment.