Theoretical support and previous research regarding how fees affect psychotherapy are reviewed. The two theories about fee effects, psychoanalysis and cognitive dissonance, have not been appropriately tested. The belief that some fee is necessary for effective psychotherapy has been disputed, but within the limits of brief therapy with particular samples and without the involvement of the therapist in the payment process. Fees appear to present a barrier to patients in entering or continuing therapy, and fees may be more important motivators to therapists than to patients. Currently the effect of fees on psychotherapy outcome is uncertain. There is a need for further research in which sliding-scale fees, private practice settings, and therapies of some duration are used and the role of the therapist in particular is explored.