We examined change in test-taking effort over the course of a three-hour, five test, low-stakes testing session. Latent growth modeling results indicated that change in test-taking effort was well-represented by a piecewise growth form, wherein effort increased from test 1 to test 4 and then decreased from test 4 to test 5. There was significant variability in effort for each of the five tests, which could be predicted from examinees' conscientiousness, agreeableness, mastery approach goal orientation, and whether the examinee "skipped" or attended the initial testing session. The degree to which examinees perceived a particular test as important was related to effort for the difficult, cognitive test but not for less difficult, noncognitive tests. There was significant variability in the rates of change in effort, which could be predicted from examinees' agreeableness. Interestingly, change in test-taking effort was not related to change in perceived test importance. Implications of these results for assessment practice and directions for future research are discussed.