The main purpose of this study was to examine the differences in students' English vocabulary learning performance as well as the instructional materials motivation, comparing the traditional lecturing method and the Augmented Reality method. This study adopted an unequal pre-test and post-test experimental design. Overall, there were a total of 42 students in two fifth grade classes in an elementary school in Central Taiwan who served as the participants of this study. Data were collected by English vocabulary tests, an instructional materials motivation questionnaire, and structured interviews. Data analyses were mixed with the quantitative and qualitative methods. The results showed that the instructional materials motivation and performance of the students taught using AR were superior to those of students taught using the traditional lecturing method. In addition, the qualitative findings of this study identified the opportunities and obstacles when adopting AR and using the traditional lecturing methods to learn English vocabulary. These findings might provide useful insights toward the successful application of English instruction in the educational realm for elementary school EFL students and teachers in Taiwan.