The rationale of the current research was to investigate English Language (EL) students' perception on their using Grammarly in Academic Writing Subject at a private university in The Mekong Delta of Vietnam. This study also desires to find out and explore the strong as well as weak aspects of Grammarly application. The mixed-method design was applied in this research. The participants of the paper were 50 EL students attended in Academic Writing Subject which was one of the compulsory courses in their university curriculum. The study employed the 15-item questionnaire with a five-point Likert scale and a semi-structured interview for data collection. The findings showed that students' perceptions on using Grammarly in their course were positive. The results also showed some strengths and weaknesses of this Grammarly application. Several challenges were discussed to recommend possible solutions to better EL students' academic writing. Implications for practical applications of Grammarly in Academic Writing Subject were addressed in this study to enhance EL students' academic writing performance. [For the complete proceedings, see ED672804.]