The interpersonal processes of learning mindfulness were explored by analyzing the transcripts of the teacher-student interactions in the Dialogue and Inquiry periods of the MBSR course, informed by video-assisted process recall interviews of teacher and students. The purpose of the study was to describe and understand the process of learning and teaching mindfulness as a joint intentional action. The study was guided by the following research questions: What is the process of learning mindfulness through the D & I period of the MBSR course? How does the social learning of mindfulness in D & I construct the experience of mindfulness? The action processes identified and described in the findings suggest that, while the mindfulness project was the super-ordinate class joint project of the Dialogue and Inquiry, it was embedded in and constituted by a concurrent relationship project made up of teacher-student, student-student and self-connections. The mindfulness curriculum was to a large part embodied by the teacher, who drew the students into joint sub-ordinate projects of noticing (attention), describing (language) and understanding (insight). Further, the joint projects of helping (compassion) and relating (connection) appeared implicitly and spontaneously. These joint projects were understood through several different psychological constructs, including attachment, attunement, mentalizing, self-compassion, acceptance, emotion-regulation and de-centering. Implications for the influential role of the Dialogue and Inquiry in both the learning of mindfulness and the positive outcomes of the MBSR intervention were drawn.