This study examined the validity of Korean students' self-assessments of their oral performance in English in a Foreign Language at the Elementary School (FLES) level. We examined the validity of 2 types of assessments: an off-task self-assessment and an on-task self-assessment. The off-task assessment asked students to evaluate their overall performance in a general and somewhat decontextualized way. The on-task self-assessment asked students to self-evaluate their performance immediately after they completed their English tasks. The results of the 2 types of self-assessments were compared both with the students' general proficiency test scores and with their teachers' assessments based on classroom observation. The results indicate that if self-assessments are administered in an on-task format, students can self-assess their oral performance more accurately than they can in an off-task format. It was also found that the on-task self-assessment was generally less influenced by student attitude/personality factors than was the off-task self-assessment.