AbstractThe goal of this paper is to show (i) how the moment‐to‐moment tracking and processing of emotionto completion—in an emotionally engaged patient–therapist dyad where the individual feels safe and known—constitutes a powerful mechanism of therapeutic transformation, and (ii) how positive emotions are sensitive affective markers of that transformational process. Evidence fromtransformational studiesis used to elaborate the vital role of positive emotions in the process of change in general, and, more specifically, in the course of therapeutic work with painful and overwhelming emotional experience. It is proposed that these emergent positive emotions are affective markers which signal the operation of healing transformational processes in psychotherapy. Several types of positive emotion that arise spontaneously during moment‐to‐moment experiential therapeutic work will be described and their role as markers of different transformational processes will be elucidated. The paper begins with examples of clinical work with emotion in AEDP (Accelerated Experiential–Dynamic Psychotherapy), an emotion‐focused and attachment‐based model of therapy that places the dyadic regulation of affect at the centre of both theory and practice. Copyright © 2004 John Wiley & Sons, Ltd.