Psychotherapy may be underutilized because people experience self-stigma-the internalization of public stigma associated with seeking psychotherapy. The purpose of this study was to experimentally test whether the self-stigma associated with seeking psychotherapy could be reduced by a self-affirmation intervention wherein participants reflected on an important personal characteristic. Compared with a control group, we hypothesized that a self-affirmation writing task would attenuate self-stigma, and thereby evidence indirect effects on intentions and willingness to seek psychotherapy. Participants were 84 undergraduates experiencing psychological distress. After completing pretest measures of self-stigma, intentions, and willingness to seek psychotherapy, participants were randomly assigned to either a self-affirmation or a control writing task, and subsequently completed posttest measures of self-stigma, intentions, and willingness to seek psychotherapy. Consistent with hypotheses, participants who engaged in self-affirmation reported lower self-stigma at posttest. Moreover, the self-affirmation writing task resulted in a positive indirect effect on willingness to seek psychotherapy, though results failed to support an indirect effect on intentions to seek psychotherapy. Findings suggest that self-affirmation theory may provide a useful framework for designing interventions that seek to address the underutilization of psychological services through reductions in self-stigma.