Given the widespread use and high-stakes nature of educational standardized assessments, understanding factors that affect test-taking ability in young adults is vital. Although scholarly attention has often focused on demographic factors (e.g., gender and race), sufficiently prevalent acquired characteristics may also help explain widespread individual differences on standardized tests. In particular, this article focuses on the role that posttraumatic stress symptoms (PSS) potentially play in standardized academic assessments. Using a military sample measured before and after exposure to war-zone stressors, the authors sought to explain test-taking ability differences with respect to symptoms of PTSD on two cognitive tasks that closely match standardized test constructs. The primary method for this analysis is based on an item response theory with covariates approach. Findings suggest that the effect for PSS is significant on both tasks, particularly for those who experience the highest levels of PSS following war-zone exposure. Findings provide potentially valuable information regarding the nature of the relationship between PSS and verbal and logical reasoning test performance. (Contains 4 tables, 2 figures and 2 footnotes.)