Writing is one of the skills alongside listening, speaking and reading that determine the ESL learners' capabilities to be proficient in English language. The skill is essential in ESL learning because it helps to facilitate the learners' expression of ideas, thoughts and emotions on a topic. However, even with a proper guidance on composing a piece of writing, it remains the most challenging skill that most ESL learners are struggling with. In order to identify the core challenges that ESL learners are facing in their writing competency, this study aims to investigate the perceptions regarding their utilisation of learning strategies to explore writing difficulties in the composing process among undergraduates at a public university in Malaysia. This study is conducted as a quantitative method and 137 participants from a public university in Malaysia responded to an online survey, administered through Google Form. The instrument used is a 5-point Likert-scale survey and rooted from Flower and Hayes (1981); Petric and Czalr (2003) which consists of 5 sections, which include: (A) respondent demographics, (B) Writing difficulties, and (C) Composing process (Before-, While-, After writing). The result of this study shows that there is a correlation between the respondents' writing difficulties during the composing process and achieving their writing goals due to their inadequate knowledge of the convention of writing in tertiary education. Based on the data obtained in this study, it could be assured that it could benefit future researchers to expand and identify other factors that influence the difficulties of writing for ESL learners.