This study investigates how Swedish upper-secondary English teachers use and perceive code-switching in the classroom, drawing on interview data from three practicing educators. The findings reveal that code-switching is a frequent, flexible, and largely spontaneous practice, influenced by factors such as lesson content, student comprehension, and emotional climate. Teachers primarily use code-switching to clarify complex concepts, scaffold understanding, manage affective barriers, and build a supportive classroom environment. While their initial attitudes toward code-switching were more rigid, all participants described a shift toward a more responsive and pragmatic approach over time. The study concludes that code-switching serves both pedagogical and interpersonal functions, supporting language development without undermining target language exposure.