Recently, researchers have started to investigate the potential interpersonal effects of mindfulness in the context of romantic relationships. However, most of these studies have focused on trait mindfulness and its association with relationship outcome measures. We employed a randomized, controlled design to investigate the effects of mindfulness practice on relationship quality. We also explored the role of partner acceptance as a possible mechanism of change and investigated whether baseline levels of trait mindfulness would moderate intervention effects.

One hundred and�thirteen participants in a romantic relationship (89% women; M_age = 27.27�years, SD = 8.31�years) living in the Netherlands participated in either a low-dose, online mindfulness-based intervention or a psycho-education control intervention for 12�days.

Results indicated that general relationship satisfaction and partner acceptance increased for both conditions (F_satisfaction(1,93) = 5.94, η²_partial = 0.06, p = 0.017; F_acceptance(1,93) = 4.63, η²_partial = 0.05, p = 0.034). Among participants with relatively low baseline levels of trait mindfulness, relationship satisfaction improved more so in the mindfulness than that in the control condition (trait mindfulness � condition: B = 0.34, SE = 0.15, β = 0.40, p = 0.024).

Short, online, self-administered mindfulness-based interventions may positively impact romantic relationship quality and might be particularly effective for participants with low levels of trait mindfulness. Theoretical and practical implications are discussed.