Teaching and learning foreign languages, including English, have always been accompanied by challenges, and these challenges have been particularly pronounced in the Iranian context. The present study aims to investigate the existing challenges in foreign language teaching and learning at one of the armed forces universities during the academic year (2020–2021). This research employs both a quantitative and a qualitative study. In the qualitative phase, interviews and content analysis were utilized, while in the quantitative phase, descriptive data analysis (percentages, frequencies, and means) was conducted. In the quantitative component, a questionnaire on the pathology of foreign language instruction at one of the armed forces universities was developed based on existing sources in the research literature to assess the perceived challenges from the learners' perspective. The reliability of the questionnaire was calculated using Cronbach's alpha coefficient in SPSS software, and its validity was established through the Content Validity Ratio (CVR), the results of which indicated acceptable values. In the qualitative phase, semi-structured interviews were employed. The findings of this study reveal that challenges exist across several domains, including the educational context, language learners, instructors, instructional approaches, educational materials and resources, as well as administrators and commanders.