Writing is a fundamental skill in language learning yet it is the biggest challenge for students these days. Students are discouraged to write their own thoughts and it leads them to become demotivated. Students' involvement is limited in any learning process, however, with the implementation of a casual learning approach, it could be possible to get students to participate in the classroom. In this 21 st century era, educators have been using various techniques and materials to enhance students' writing. Therefore, educators believe that using social media as a platform for teaching and learning might be helpful to make the lessons fun and interactive. Thus, this paper aims to investigate the use of Twitter as a casual learning approach in enhancing students' writing skills. A study was conducted among 20 undergraduate students to investigate if Twitter makes any difference in enhancing their writing skills and their motivation to write. ESL lessons via ZOOM were conducted with the integration of Twitter's threads as the casual learning approach to help students to be more interested in writing, which in a way will help to enhance their writing skills. A questionnaire was later distributed to the students to investigate their feedback on the use of Twitter as a platform to help them to enhance their writing skills. Findings have shown that students are more comfortable to have Twitter as one of the platforms to help them to enhance their writing skills. It can be seen that the students participated more when Twitter was used in the lessons as part of the writing activity. One of the reasons might be because of the flexibility and the casualty. The end result of this study shows that utilizing Twitter in ESL teaching and learning gives a positive impact for both educators and the students.