The purpose of this paper is to establish ethical guidelines for the use of paradoxical interventions in psychotherapy. These are defined as interventions which are counterintuitive, coercive, and which require non-observance by the client. Arguments are developed to show that such interventions are associated with a psychology that understands individuals solely in terms of their relationship: a 'strong interactionist' position. Ethical principles consistent with such a position are considered, and from these it is derived that: paradox is an ethical technique (...) with resistive patients; it requires consent; its content should be consistent with general ethical principles, especially those of beneficence and non-maleficence; non-paradoxical techniques should be preferred when possible; and it should not be used as an assessment procedure. It is concluded that research is needed to explore the effect of such ethical guidelines of effectiveness, though preliminary impressions are encouraging. (shrink)