The current qualitative study examined the role of teacher concern in Iranian institute English as a Foreign Language (EFL) students’ motivation and anxiety. The study involved 24 participants who participated in a focus group interview to express their opinions on this topic. Thematic analysis was applied to derive seven themes for each role of teacher concern - facilitator or debilitator - based on the perceptions of the students. The findings revealed that teacher concern can have both positive and negative effects on students’ language learning process, depending on the circumstances. It can serve as a motivator, enhancing students’ motivation, or as a hindrance, demotivating them. Teacher concern is shown to be a highly sensitive criterion, and teachers must be mindful of their students' characteristics and the level of care they demonstrate. Teacher concern is likened to a double-edged sword, capable of both motivating and demotivating students. This study emphasized the importance of understanding the impact of teacher concern on students’ language learning and suggests that teachers should be cautious in their approach, taking into account individual student needs and providing appropriate levels of care and support.