Much more research has been done on the effectiveness of therapeutic techniques than on the client characteristics which mediate the effectiveness of these techniques. Research on client characteristics has concentrated on demographic variables rather than psychological characteristics such as client reactance. The Therapeutic Reactance Scale was developed to measure psychological reactance. An initial pool of 112 items was developed and administered to 130 college students. A subsequent item analysis identified 28 items as showing item-total test correlations of .30 or above. A factor analysis resulted in the identification of two factors, labeled behavioral reactance and verbal reactance. Internal consistency reliability coefficients ranged from .75 to .84 while test-retest reliability coefficients ranged from .57 to .60. Additional divergent validity data showed low correlations with the Beck Depression Inventory and the Spielberger State-Trait Anxiety Inventory. The results indicated that there does seem to be an identifiable construct of psychological reactance which is an individual difference characteristic stable over time. The concept of psychological reactance has particular application to paradoxical counseling, as the theory behind the use of paradoxical interventions predicts that some paradoxical techniques would be more applicable to reactant clients than compliant ones. Four pages of references are included. (Author/NRB)