||The beneficial consequences of maternal sensitivity for infant social and emotional development are well-known, as is the notion that stress may impair a mother's ability to provide sensitive care for her infant. Less is known about whether some mothers may be more susceptible to parenting-related stress than others. The effect of stress on maternal sensitivity may depend on the past maternal bonding of the mother. Data from this study come from a sample of 45 women and their 7-month-old infants. Mothers underwent a control or an acute stress writing task, then were evaluated for maternal sensitivity during a face-to-face interaction, the still-face paradigm. Maternal sensitivity was assessed using the Global Scale of Mother Infant Interactions, containing nine individual scales. Past maternal bonding was determined using the Parental Bonding Instrument (PBI). One significant interaction was found that revealed that, for those in the control condition, mothers with a history of high-quality maternal bonding were more accepting of their infants' behaviors than mothers with a history of low-quality maternal bonding. For those in the stress condition, mothers with a history of low-quality maternal bonding provided higher levels of maternal sensitivity than mothers with a history of high-quality maternal bonding. While significant results were found in only a portion of the variables tested, this analysis could become the foundation of future studies. Results provide us with a more complete picture of how acute stress can affect maternal sensitivity, and for whom stress exposure may have more of an impact.