The repetition compulsion—the propensity to repeat formative early life experiences, for good or ill—is one of psychoanalysis's most important contributions to the understanding of human nature. However, its broader applications to psychodynamic psychiatry and psychotherapy have received little attention. In fact, it is a concept widely applicable to the understanding and treatment of psychiatric disorders, since maladaptive or self-defeating repetitions are the stuff of psychopathology. This article will discuss the repetition compulsion as a core concept of psychodynamic psychiatry. Principles of the compulsion to repeat will be applied to the dynamics of personality disorders, and will be illustrated by discussion of its usefulness in understanding and treating several common and representative psychiatric conditions: reactive depression, punitive superego function, and traumatic neurosis. These conditions illustrate the reparative, retributive, and restorative functions of the compulsion to repeat.