Modern teaching practices emphasize learner autonomy and learner-centered approaches to language learning. Such teaching methods require corresponding assessment approaches. Self-assessment is viewed as an assessment mode which matches modern learner-centered teaching methodologies. However, the validity and reliability of self-assessments are not yet conclusively established. This study aimed to provide validity and reliability evidence for self-assessments among Iranian EFL university learners. The Common European Framework of Reference (CEFR) Self-Assessment Grid was translated into Persian and was given to a sample of Iranian undergraduate students of English. A C-Test battery containing four passages was used as a criterion for concurrent validation. Self-assessments of university EFL learners were examined for internal consistency and test-retest reliability. Findings showed that while self-assessments are highly reliable, they lack validity as evidenced by low correlations between components of the self-assessment grid and the C-Test. The implications of the study for the application of self-assessments in foreign language education are discussed.