The general aim of the study was to investigate the feasibility and accuracy of self-assessing thinking/reasoning skills and to provide information about the psychometric properties of one instrument designed to self-assess these skills. This objective was accomplished by examining the relationship of the self-assessment to cognitive measures of reasoning skills. A sample of Graduate Record Examinations (GRE) General Test takers (n = 342) completed a battery of reasoning tests along with a 20-item self-assessment of thinking skills, which had been developed empirically on the basis of a survey of graduate faculty. The results revealed only weak relations (rs in the .20s) between the self-assessment and cognitive test scores. Possible reasons are proposed for the lack of any strong relation.