Students of middling achievement who achieve intermediate results on the Basic Competence Test, a national high-stakes entrance examination in Taiwan, experience the highest test anxiety. The present study explored why such students experienced greater test anxiety and the source of that anxiety. A questionnaire survey was administered to 5,220 Taiwanese Grade 9 students in order to collect data on test anxiety, reasons for test anxiety, time spent on study, and frequency of cram school attendance. Data regarding students’ achievement on the Basic Competence Test were also collected. The research findings were as follows: First, students of middling achievement had higher test anxiety than their peers. Second, the reasons for their test anxiety also varied according to levels of academic performance–students with middling achievement experienced anxiety about the possibility of not being admitted to a state school (which are more prestigious than private schools in Taiwan). Third, students of middling achievement spent approximately the same amount of time studying as top students but more time studying at cram schools. The findings indicate that students of middle achievement might experience greater test anxiety because they spend more time studying but still run the risk of not being admitted to a state school.