Researchers disagree whether the correlation between cognitive test anxiety and test performance is causal or explainable by skill deficits, which lead to both cognitive test anxiety and lower test performance. Most causal theories of test anxiety assume that individual differences in cognitive test anxiety originate from differences in self-perceived competence. Accordingly, in the present research, we sought to temporarily heighten perceptions of competence using a priming intervention. Two studies with secondary- and vocational-school students (Ns = 219 and 232, respectively) contrasted this intervention with a no-priming control condition. Priming competence diminished the association between cognitive test anxiety and test performance by heightening the performance of cognitively test-anxious students and by lowering the performance of students with low levels of cognitive test anxiety. The findings suggest that cognitively test-anxious persons have greater abilities than they commonly show. Competency priming may offer a way to improve the situation of people with cognitive test anxiety.