Perceptions of power imbalance are common in relationships. We used the relational model of mindfulness to examine links between marital perceptions of power, relational and sexual well-being and to evaluate whether trait mindfulness and sexual mindfulness moderate these associations. Using a nationally representative sample (N = 1,519 couples at Wave III) of mixed-sex newlywed couples, an actor-partner-interdependence model indicated that trait mindfulness and state sexually mindful awareness buffered the link between men's and women's own perceived power imbalance and relational well-being. Sexually mindful non-judgment, however, accentuated the negative association between perceived power imbalance and sexual well-being for men. We discuss the need for therapists to consider the need to encourage mindful awareness to attenuate perceptions of power imbalances and to evaluate how sexually mindful non-judgment influences men's feelings of sexual well-being. Therapeutic implications of these findings are also discussed.