BackgroundStudent emotions play a vital role in learning and have been linked to achievement outcomes, but research on the relationship between emotions (other than anxiety) and high-stakes standardized tests is sparse. AimsWe investigated whether emotions experienced during learning predict later performance on a high-stakes, mandatory, standardized test. SampleWe used two cohorts comprising a total of 102,007 grade 7–9 U.S. students. MethodsWe used experience sampling methods to measure 14 emotions (e.g., boredom, confusion, hope) as students engaged in technologically-enhanced learning as part of their math classroom instruction. ResultsStudents’ self-reported positive and negative emotions, positively and negatively predicted test scores, respectively, after covarying prior achievement and sociodemographics. However, there was limited evidence for indirect paths between prior achievement, emotions, and subsequent achievement. ConclusionsOur findings corroborate central predictions of major theories on emotions and learning that highlight the importance of emotions to learning processes and outcomes.