This article explores the impact of letter writing on therapeutic boundaries. Letters challenged and extended the spatial and temporal boundaries of the therapeutic relationship, and especially the boundary between the personal and the professional, resulting in greater relational connectedness and therapeutic intimacy between the author as therapist and his client participants. By crossing boundaries traditionally posited to keep clients safe, letter writing evoked a carefully considered use of boundary that, perhaps paradoxically, brought the author and the participants into a fuller relationship with self and with each other. A revisioning of therapeutic boundary that challenges "professionalism" and patriarchal constructions of boundary is followed by an exploration of how letters contributed to therapeutic intimacy by giving expression to therapist availability, mutuality, and vulnerability. The experiences of five of the author's clients who agreed to be interviewed are used to illustrate and enrich this narrative.