This study examined likelihood of high school students' gender, levels of academic achievement, perfectionism and perceived social support in predicting their degree of test anxiety. Participants were 505 students from high schools in the Ankara metropolitan area. The Test Anxiety Inventory, Multidimensional Perfectionism Scale and Perceived Social Support Scale-R were used for data collection. In addition, the Personal Information Form (PIF) was given to the participants to obtain demographic information. Regression analysis was used for data analysis. Significant relationships were found between test anxiety; and perfectionism, social support and academic achievement. Stepwise regression analysis showed that perfectionism, gender, academic achievement, perceived support from friends and support from teachers significantly contributed to the variance in test anxiety. Findings were discussed in accordance with the existing literature and implications for researchers and practitioners were articulated. (Contains 2 tables.)