Because personality disorders are associated with significant impairment in interpersonal relationships, special issues and problems arise in the formation of a therapeutic alliance in the treatment of patients with these disorders. In particular, patients with narcissistic, borderline, and paranoid personality traits are likely to have troubled interpersonal attitudes and behaviors that will complicate the patient's engagement with the therapist. While a strong positive therapeutic alliance is predictive of more successful treatment outcomes, strains and ruptures in the alliance may lead to premature termination of treatment. Therefore, clinicians need to consider the patient's characteristic way of relating in order to select appropriate interventions to effectively retain and involve the patient in treatment. Research has shown not only the importance of building an alliance but also that this alliance is vital in the earliest phase of treatment. The author first reviews several definitions of the therapeutic alliance with reference to how they apply to the treatment of patients with personality disorders. Issues relevant to forming a therapeutic alliance with patients with personality disorders are then discussed in terms of the three DSM-IV-TR personality disorder clusters. However, the author notes that these categories do not adequately capture the complexity of character pathology and that clinicians also need to consider which aspects of a patient's personality pathology are dominant at the moment in considering salient elements of the therapeutic alliance. In dealing with Cluster A personality disorders (schizotypal, schizoid, and paranoid personality disorders), what is most relevant for alliance building is the profound impairment in interpersonal relationships. The Cluster B "dramatic" personality disorders (antisocial, borderline, histrionic, and narcissistic) are all associated with pushing the limits. Consequently, clinicians need to exercise great care to avoid crossing inappropriate lines in a quest to build an alliance with patients with one of these disorders. Patients with Cluster C "anxious/fearful" personality disorders (avoidant, dependent, and obsessive-compulsive personality disorders) are emotionally inhibited and averse to interpersonal conflict. These patients frequently feel guilty and internalize blame for situations even when there is none, a tendency that may facilitate alliance building because the patients are willing to take some responsibility for their dilemma and may engage somewhat more readily with the therapist to sort it out, compared with patients with more severe Cluster A or B diagnoses. The author then reviews considerations relevant to treatment alliance that arise in the different treatment approaches that may be used with patients with personality disorders, including psychodynamic psychotherapy/psychoanalysis, cognitive-behavioral therapies, and psychopharmacology. The author also discusses issues, especially splitting, that arise in the alliance when patients with personality disorders are treated in inpatient psychiatric hospital settings.