Using a sample of 497 college students, we measured test-taking emotions (anger, worry, pride, enjoyment) after the first third, second third, and last third of a low-stakes cognitive test of sociocultural knowledge. We examined the simultaneous change in emotions and whether change in emotions predicted subsequent test-taking effort and test performance. Latent growth models indicated that, on average, enjoyment and anger increased, whereas pride and worry decreased during the test. There was significant variability in individual change about these averages. Positive correlations were observed between change in worry and anger and change in pride and enjoyment. Structural equation models indicated that all initial emotions and gains in pride during the test influenced subsequent effort, whereas initial worry, anger and enjoyment, change in pride and enjoyment, and effort influenced test scores. The findings emphasize the importance of assessing change in emotions and the mediation mechanism of effort when modeling test performance.