A considerable body of research in EFL assessment seems to be motivated by the notion of self-assessment (see Sung et al., 2010, for example). In this research, essay writings of sixty-four major English learners were subjected to self- and teacher-assessments employing holistic vs. category-based scoring. The average of teacher scorings was used as the criterion for validity. Statistical analysis indicated that self-assessments were fairly valid, but not reliable. Also, holistic and category-based self-assessments correlated but not very highly. Findings imply that while self-assessment may provide a valid method for measuring learner performance in EFL, an unthinking application of self-assessment as a primary means of measuring learners’ performance would be questionable. Another implication might be that in the cautious application of self-assessment as a partial representation of learners’ performance, teachers and testers may instruct the learners to use both types of scoring as they empirically evoke similar self-judgments on the test-takers’ part.