Abstract The testing effect is a robust cognitive strategy for improving recall from memory. Most of the literature about the testing effect (repeated retrieval practice) focusses on retrieval practice of academic, subject content. Test anxiety can occur in many individuals and from age seven upwards and students who are high in test anxiety account for 10-20% of a school population. The intervention in this study used retrieval practice to teach 10-to 11- year-olds about the testing effect itself; in effect, using the testing effect to teach the testing effect to try and increase feelings of self-efficacy in test taking and reduce the worry or cognitive element of test anxiety. The impact of the intervention was measured with a new Self-efficacy in Test Taking instrument and an adapted version of the thoughts’ subscale from the Children’s Test Anxiety Scale using pre-test and post-test participant responses. The intervention was delivered in the classroom over a period of six weeks and aimed to teach 10-to 11- year-olds to believe in their test taking abilities, that their “testing routes were well-oiled”. There was a control group. The results show that for both the intervention and control group, the worry element of test anxiety reduced and self-efficacy in test taking increased at the post-test stage. The intervention increased feelings of test taking self-efficacy significantly for students who are high in test anxiety when measured with the Little Self-efficacy in Test Taking subscale.