This mixed-method pre-test/post-test experimental study aims to investigate the effects of Augmented Reality (AR) supported English as a foreign language course on 42 high school students' attitudes towards the English language course, on learners' beliefs of self-efficacy in English and on their motivation towards the instructional materials used in the class. Following a 10-week teaching period, both the quantitative and the qualitative results showed that the AR-enhanced foreign language education significantly improved students' attitudes towards the English language course and increased their beliefs of self-efficacy in the English language. The results also revealed that the implementation of AR technology had a significant positive impact on the motivation levels of learners towards the instructional materials in the classroom. The AR technology in the class served as an interactive and entertaining tool which transformed a monotonous learning atmosphere into an engaging and effective one. Finally, the findings confirmed that AR-driven listening and speaking activities could lead students to gain a good understanding in English language topics and that teachers could make use of AR not only in classrooms but also for extra-curricular activities.