The relationship between several individual difference variables and test performance using computerized adaptive testing (CAT) was studied with 208 South Korean college students. The general individual difference variable selected was test anxiety, and the math-related individual difference variables were mathematics aptitude, math test anxiety, and math self-concept. Computer-related individual difference variables were computer literacy, computer anxiety, and computer experience. The CAT was an algebra test. Test anxiety and other individual difference variables were measured with instruments translated into Korean for the study. The seven difference variables and their squares were submitted to an analysis using the RSQUARE Procedure from Statistical Analysis System software. Math aptitude, math self-concept, math test anxiety, and computer literacy, in that order, were significantly related to test performance using CAT, but test anxiety, computer experience, and computer anxiety were not. Results suggest that the relationship between individual difference variables and test performance using CAT may be curvilinear. Two tables present analysis results. (Contains 27 references.) (SLD)