Objective: Intelligence measures have a high-moderate correlation with academic achievement. The purpose of this study was to examine if anxiety on the day of testing moderates the relationship between intelligence and academic achievement. Method: Six hundred sixty-five participants (mean age = 22.77, SD = 5.99; 51% female; 87% white) at a large southeastern university were administered the Weschler Adult Intelligence Scale-Third Edition (WAIS-III), Woodcock-Johnson-Third Edition (WJ-III), and the State-Trait Anxiety Inventory (STAI). Results: Presence of moderation was examined using hierarchical regression. An interaction term WAIS-III x STAI was created to test for moderation. Results indicated that STAI scores moderates the relationship between WAIS-III and broad math achievement (t = −2.07 (661), p = .039, ΔR2 = .004). Further, STAI moderates the relationship between WAIS-III and academic fluency (t = −1.97 (661), p = .0492, Δ R2 = .005). Lastly, STAI moderates the relationship between WAIS-III and math fluency (t = −2.45 (661), p = .025, ΔR2 = .007). All other WJ-III measures were not significantly moderated by the STAI. Gender was not found to be a second level moderator. Probings of the three interaction results revealed similar patterns of results. Specifically, the slope representing the positive relationship between intelligence and achievement was flatter amongst participants who reported being more anxious on test day Conclusion(s): Acute measures of anxiety moderated the relationship between intelligence and broad math achievement, as well as academic fluency and math fluency regardless of gender. The increase of anxiety during testing may account for poorer performance in mathematics and overall measures of academic fluency.