Therapeutic alliance refers to the interactional and relational processes operating during therapeutic interventions. It has been shown to be a strong determinant of treatment efficacy in psychotherapy, and evidence is emerging from a range of healthcare and medical disciplines to suggest that the construct of therapeutic alliance may in fact be a variable component of treatment outcome, engagement and satisfaction. Although this construct appears to be highly relevant to aphasia rehabilitation, no research to date has attempted to explore this phenomenon and thus consider its potential utility as a mechanism for change.