The aim of this research was to investigate TESL pre-service teachers' perceptions of the Common European Framework of Reference for Languages (CEFR) implementation in primary ESL classroom. The study explored pre-service teachers' awareness, challenges, and potential solutions to overcome any limitations. The research was conducted in five Institutes of Teacher Education in Malaysia and involved 203 participants who were majoring in Teaching English as Second Language (TESL) for Bachelor's Degree in Teaching or Program Ijazah Sarjana Muda Perguruan (PISMP). The study employed a quantitative methodology in data gathering, using a set of questionnaires that utilized a 5-Likert scale. The researchers used descriptive statistics including percentage, mean, and standard deviation to analyze the data. The study found that TESL pre-service teachers had an agreeable level of awareness of CEFR (M = 4.12), perceived the challenges in implementing CEFR (M = 3.84), and identified potential solutions to overcome the issues (M = 4.47). The study cast significant implications on stakeholders such as the Ministry of Education and the Institutes of Teacher Education in Malaysia. The research suggests that these stakeholders should provide pre-service teachers with sufficient exposure to CEFR implementation and identify the challenges that they face when integrating CEFR into primary ESL classroom. Overall, this research highlights the importance of investigating TESL pre-service teachers' perceptions of CEFR implementation. Additionally, the study provides suggestions for future research in this area.