Using a new psychoanalytic perspective, the author explains how irrational unconscious guilt originates, how it produces psychopathology, and how it is mastered in psychotherapy. According to this perspective, unconscious guilt is a product of repressed irrational beliefs derived from traumatic childhood experiences. The author emphasizes the role of guilt as a source of resistance and transference, and he explains patients' unconscious efforts to master problems with guilt through an ongoing process of testing the therapist. Therapeutic outcome significantly depends on the degree to which therapists pass patients' tests and accurately analyze patients' guilt-based resistances and transferences. The author briefly describes an empirical study based on these concepts.