The authors examine the ethical issues in choosing between individual and social unit (marital and family) therapies. Although usually neglected in the literature, these ethical questions are important and complex. A general systems perspective is used to provide a framework for ethical analysis. The core of the ethical problem is shown to be the interdependence and irreducible conflict inherent between the individual and social unit levels. The authors outline a general systems approach to identification and consideration of these ethical issues in clinical practice.