This study explored the moderating effect of psychological reactance on the success of traditional and paradoxical mental imagery treatments that were aimed at reducing anxiety in athletes. Intramural college basketball players (N = 73) were recruited through advertisements for a free-throw contest, and their anxiety and free-throw performance were measured following treatment in one of three groups: confidence imagery, paradoxical imagery, or control. As predicted, in the paradoxical condition, high-reactant athletes reported having significantly lower somatic state anxiety and significantly higher state self-confidence than did low-reactant athletes. In contrast, high- and low-reactant athletes did not differ in their anxiety scores in both the confidence imagery and control conditions. Results suggested that reactance does moderate the effect of the success of traditional and paradoxical imagery treatments for reducing athletes’ anxiety.