This research project involved a mixed-methods study investigating language-related challenges of first-year students at an English Medium Instruction (EMI) university in Hong Kong. The two-phased sequential study employed a questionnaire survey and semi-structured student interviews. The survey and interview findings indicate that first-year students face a number of language-related academic challenges during their first year at an EMI university in writing, reading, speaking, and listening, many of which appear to stem from lower levels of vocabulary knowledge in English, unfamiliarity with academic and technical terminology, and limited exposure to varieties of English. Additionally, the findings suggest that these challenges can vary significantly based on background and first language, relating specifically to three different demographic student groups: local Hong Kong Cantonese-speaking students, Putonghua-speaking mainland Chinese students, and non-Chinese speaking local and international students.