This study aimed to find out the effect of using authentic materials in learning English, especially for reading comprehension. Besides, the students’ motivation in reading was also explored. This study employed a quantitative experimental design using a one-group pre-test/post-test approach. The population consisted of 11 first-grade classes at a senior high school in Langsa. One class of 25 students was selected through purposive sampling as the sample. A reading test in the form of multiple choices and a student response questionnaire were administered to collect the data. The results showed that there is a good improvement in students’ reading comprehension. This finding is supported by the difference between the pre-test and post-test scores. Students’ average scores improved from 56.8 (pre-test) to 80.8 (post-test), surpassing the minimum competency standard. Students also reported increased interest, motivation, and vocabulary acquisition when using authentic materials. Findings suggest that authentic materials can enhance reading comprehension and student motivation. This study contributes to EFL pedagogy by demonstrating the effectiveness of authentic materials in improving reading comprehension and motivation. However, the study was limited to one class and may not generalize to broader populations.