This inquiry chose three major Korean engineering universities to explore engineering students’ perceptions of English-medium instruction (EMI) and L1 use in EMI classes and to make proposals for the directions that Korean engineering schools should take in relation to EMI. A questionnaire survey was conducted among the undergraduate students of the three universities. Five hundred twenty-four students partook in the survey, and the results display that more students felt inadequate about their English skills than adequate and that the majority of the students chose Korean-medium instruction over EMI and did not find EMI advantageous for their English skills. Even so, most of the survey participants deemed that EMI should be upholded but with changes in the schools’ mandatory policies. In addition, the students without distinction as to school were supportive of L1 use in EMI classes: approximately 90% of the respondents from each school believed that L1 should be employed to ease their learning. KEYWORDS: Korean engine