This study was set to prepare and validate the Achievement Emotions Questionnaire-Foreign Language Class (AEQ-FLC) for use in the context of English as a foreign language (EFL). The AEQ is largely used and validated with different cohorts of students in different domains. However, despite its need for valid measurement instruments to serve the increasing interest in researching second language emotions, the language classroom is a domain that has been largely overlooked in the validation project. To fill this measurement lacuna, data were collected from 748 Iranian EFL learners, and the collected data were submitted to confirmatory factor analysis (CFA). The CFA results indicated that the psychometric properties of the AEQ-FLC could be substantiated, and that its structure was invariant across gender and learning context. The implications for the use of the AEQ-FLC in both research and practice are discussed.