Integrating theorizing on mindfulness and work relationships, we build a multilevel model of how mindfulness shapes interpersonal interactions and work relationship trajectories over time. Our framework of mindful relating yields three approaches an individual may utilize during an interpersonal interaction at work, based on the extent to which they incorporate the mindful qualities of attention and decentering. We theorize how the extent to which interaction partners are (in)congruent in their mindful relating approaches associates with interaction quality (positive, ambivalent, indifferent, and negative)—and how over time, this shapes the trajectory of a work relationship. We further posit that empathy, response flexibility, and emotional regulation transmit the effects of mindful relating and drive interaction quality. From a contextual perspective, we explore the roles of power dynamics and negative shock events as factors likely to impact how interactions over time collectively inform the trajectory of relationships. Finally, we explicate how our theory‐building can guide future work, and make specific recommendations for theoretical and empirical advancement.