The current study explored differences in test anxiety on high-stakes standardized achievement testing and classroom testing among elementary school children. This is the first study to directly examine differences in student test anxiety across two testing conditions with different stakes among young children. Three hundred and thirty-five students in grades three through five participated in the current study. Wilcoxon Signed Rank Tests revealed that as a whole, students reported significantly more overall test anxiety in relation to high-stakes testing than classroom testing on two different measures of test anxiety (r = -0.21 and r = -0.10). Students also reported significantly more cognitive (r = -0.20) and physiological (r = -0.24) symptoms of test anxiety in relation to high-stakes testing than classroom testing. Teachers' perceptions of student anxiety were also examined in the current study and consistent with student self-reported test anxiety, results indicated that teachers believed students experienced significantly more anticipatory anxiety in relation to high-stakes testing versus classroom testing. Analyses of variance indicated that low test-anxious students performed significantly better on high-stakes testing while there was no difference in performance between moderate and high test-anxious students. Further, multiple regression analyses indicated that test anxiety contributed significantly to English Language Arts test performance among third and fourth grade students and Math test performance among third grade students. Additionally, the current study examined the relationship between test anxiety and student demographic characteristics. Results of multiple regression analyses indicated that student gender and grade significantly predicted student test anxiety, while student ethnicity, educational verification, and socioeconomic status did not. The current study also examined the relationship between three measures of test anxiety and differences in how three test anxiety classification systems sorted students into low, moderate, and high test-anxious groups. Correlation analyses indicated that the Children's Test Anxiety Scale for Children (CTAS), Test Anxiety Scale for Children (TASC), and Behavior Assessment Scale for Children, Second Edition, Test Anxiety subscale (BASC-2-TA) were strongly related to one another (rs > .70). However, chi-square goodness of fit tests revealed that there were significant differences in the proportions of students classified as low, moderate, and high test-anxious across classification systems. Using the CTAS and TASC to classify students, prevalence rates of high test anxiety in relation to classroom testing ranged from 11 to 21 percent, respectively. Similar rates of students were classified as highly test-anxious across the high-stakes and classroom testing conditions using the CTAS. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]