Despite substantial evidence that group therapy is effective, many individuals are reluctant to join groups, and clinicians are reluctant to refer patients to them or to lead a group themselves. This article investigates the obstacles to participation in group therapy. It focuses primarily on the deeply personal elements of this hesitation for potential group members, which include social anxiety, fear of anger from other group members, dread of experiencing shame or humiliation, and desire for individual attention. Clinicians, as well, are reluctant to lead groups, because they feel insufficiently trained and may fear the experience of inadequacy, shame, and humiliation. These obstacles to participation are often driven by powerful components of transference and countertransference.