Objective: Maternal attachment representations and children’s attachment to their mothers have been shown to be related while this association varies according to socioeconomic risk factors that these mother-child dyads are experiencing. In this regard, this study aims to investigate the intergenerational transmission of attachment between highly disadvantaged incarcerated mothers and their co-residing children and the mediating role of maternal sensitivity in the relationship between maternal and children’s attachment representations. Method: The study sample consists of 84 incarcerated mothers and their co-residing children. The maternal attachment was evaluated using the Doll Story Completion Task. Children’s attachment and maternal sensitivity were assessed based on a 45-minute semi-structured mother-child interaction observation and rated through structured coding instruments. Results: Hierarchical regression analyses revealed that mothers’ anxious and avoidant attachment positively predicted children’s disorganized attachment behaviors. Moreover, analyses showed that maternal sensitivity did not mediate the relationship between maternal and child attachment representations. Conclusion: Findings partially supported the discussion emphasizing that attachment transmission, as well as the mediating role of maternal sensitivity on this transmission, appeared to be weaker for disadvantaged mother-child dyads. Implications for future intervention programs aiming to support the attachment security and reduce the disorganization of children co-residing with their incarcerated mothers are discussed.