The Westside Test Anxiety Scale is a brief, ten item instrument designed to identify students with anxiety impairments who could benefit from an anxiety-reduction intervention. The scale items cover self-assessed anxiety impairment and cognitions which can impair performance. Correlations between anxiety-reduction as measured by the scale and improvements in test performance were used as the validation criteria. Subjects were from two diverse samples: 25 anxious college students, many on academic probation, and 34 anxious fifth grade students. Each sample was divided into Intervention and Control groups, with the Intervention groups receiving an anxiety-reduction training. Anxiety scores and test scores were attained prior to the study and after Interventions. Anxiety reduction benefits as measured by the Westside scale correlated 0.49 and 0.40 with test gains for the college and fifth grade samples respectively. The average correlation was r = 44, indicating that changes in the Westside scale accounted for 20% of changes in these objective tests. The solid validation coefficient combined with the replication in two diverse student populations indicate that the Westside scale is a reliable and valid measure of test-anxiety impairment. As the scale is brief and easily administered, is public access and free of charge to schools, and is shown to be a reliable and valid measure, it is recommended that the Westside Test Anxiety Scale be considered by intervention programs to screen for test-anxiety impairments. The Westside Test Anxiety Scale is appended.