The purpose of this study was to investigate the effects of shadowing using authentic listening materials, TED talks, on L2 listening abilities in the EFL high school context. It also examined whether shadowing with authentic materials had a positive influence on students’ interest and self-confidence. This study was conducted with 70 Korean senior year high school students, providing eight weeks of treatment. The experimental group had the shadowing instruction and the control group had the conventional listening instruction focusing on translation and grammar. Two different types of tests were employed, the National high school English listening tests and TOEFL listening tests. The data were collected through the results of listening tests and questionnaire. The results suggested that shadowing with authentic materials effectively improved students’ listening comprehension skills, while listening instruction itself was meaningful. The results also showed that, w ith the longer texts of TOEFL, prolonged practice for more enlarged short-term memory along with test-taking strategies such as note-taking were necessary. The experimental group showed significantly higher changes in self-confidence than the control group. This study therefore considered the combination of a shadowing technique and authentic listening materials as an effective supplementary model for listening instruction.