Test-taking effort relates to performance on low-stakes tests; thus, researchers and assessment practitioners have investigated what influences students to put forth effort when completing these tests. Using a longitudinal design, we evaluated the often-cited effect of perceived test importance on test-taking effort. More specifically, a 29-item low-stakes institutional accountability test was split into three subtests. College students completed measures of perceived test importance and test-taking effort after each subtest, in addition to measures of test emotions (anger, pride). Emotions were assessed and modeled to provide a rigorous test of the unique relation between perceived test importance and effort. Using a panel model with autoregressive effects, we found perceived test importance had no significant direct or indirect effects on effort during the test. Emotions, however, were predictive of subsequent effort. These results can inform interventions to increase test-taking effort by calling attention to variables other than perceived test importance.