We investigated processes underlying performance decrements of highly test-anxious persons. Three experiments contrasted conditions that differed in the degree of activation of concepts related to failure. Participants memorized a list of words either containing words related to failure or containing no words related to failure in Experiment 1. In Experiment 2, all participants initially memorized words related to failure, but one experimental condition subsequently required the intentional forgetting of these words, thereby, decreasing the words' activation in memory. The performance of highly test-anxious participants in unannounced cognitive ability tests following the memorizing phase profited from the activation of failure-related concepts. Experiment 3 replicated this finding by contrasting a condition priming failure-related concepts with a neutral control condition. The results point to a mechanism of suppressing worrying thoughts that is detrimental to test performances of highly test-anxious persons. Bringing the feared threat of failure to their awareness prevents that suppression.