Purpose: The purpose of this study is to contribute to the ongoing debate about the instructional languages in Moroccan education through exploring graduate students' attitudes towards the potential use of English-medium instruction (EMI) in Moroccan science universities. Design/methodology/approach: In this study, 17 master and doctoral students have been interviewed to explore attitudes towards EMI implementation in Moroccan higher education. The data were collected and analysed based on constant comparative method, which belongs to the grounded theory methodology. The method is based on organizing the raw data into categories according to shared attributes while constantly comparing the parts of the data as they occur. The objective is to formulate new hypotheses and theories about the phenomenon of interest. Findings: The findings of this study reveal that although graduate students hold positive attitudes towards the future implementation of EMI in higher education, they think students are not prepared for such a switch in the language of instruction given that they have been taught through either Arabic or French in lower levels. Hence, they suggest gradual implementation of EMI in lower levels and introduction of English as a foreign language instead of French at primary level. Originality/value: Most of the previous studies on bilingual education and EMI have investigated non-Anglo-Saxon contexts, where English is the major foreign or second language. The researchers could not have located any study which investigates the possibility to implement EMI in post-colonial contexts, where other foreign languages, bearing colonial conations, are more dominant than English. This study presents the case of Morocco, where French, rather than English, is the dominant foreign language not only in education but also in different other domains of life.