We examined the association between the quality of maternal representations of attachment evaluated by the Adult Attachment Interview (AAI) and mother styles of regulating attention and emotion during free play with objects in 41 mother dyads when infants were nine months old. The secure mother dyads showed a greater duration of engagement matches, with more positive matches, and a greater capacity to move from non-matched to matched states. Secure mother dyads demonstrated greater involvement in play with objects than insecure mother dyads. Insecure mother dyads showed a greater duration of mismatches and spent more time in negative matches. Correlations between maternal AAI scores and the variables studied also showed that the maternal Passivity and Unresolved scales were associated with less adequate dyadic attention and emotion regulation, while the maternal Coherence scale was associated with more adequate dyadic attention and emotion regulation.