Language anxiety is often experienced by EFL students, especially during speaking activities. The impact and contributing factors may vary for each student depending on their individual experiences. Therefore, this study was conducted to investigate the perceived impact of language anxiety on English proficiency development and to identify the internal and external factors that contribute to it. Using purposive sampling, 8 students from the English Language Education Department at UIN Ar-Raniry Banda Aceh who had taken the Advanced Language Skill course were selected as participants. This research employed a qualitative method using semi-structured interviews as the data collection instrument. This study found that language anxiety affected students’ English proficiency development, particularly in speaking. Emotional and behavioral symptoms such as nervousness, hesitation, mental block, and avoidance emerged during speaking tasks. These reactions limited their classroom participation and reduced opportunities for language practice. The internal factors contributing to anxiety included fear of making mistakes, low self-confidence, negative self-perception, and lack of preparation. The external factors involved fear of negative evaluation, classroom atmosphere, teacher behavior, and the speaking task format. Most students reported that their anxiety increased when they were required to speak in front of others or when corrected directly by the teacher. These conditions hindered their ability to express themselves and slowed their language development. The findings highlight the need for supportive teaching strategies and a positive classroom environment to reduce students’ anxiety and enhance their English proficiency.