This paper reports on the effects of using wiki-based process writing in Singapore's Chinese as a Second Language (CSL) scenarios. A group of 32 Secondary 1 (Seventh Grade) students ("Students") received various forms of online scaffolding at different steps of the writing process over two years. A whole set of teaching materials on 45 writing skills was developed and uploaded to the Wiki platform through five recursive cycles. In each cycle, the students were encouraged to apply skills they learned via Wiki platform in their writing and afterwards work as a team in the platform to peer-review each other's first draft. With feedback received from peer revision, students proceeded to edit their first draft, focusing on the content of narratives and the appropriateness on their use of micro writing skills. The scaffolding decreased as the project progressed. Students' pre-, mid- and post-writing tests were marked and compared. The authors analyzed the impact that the feedback in the process had towards the students' overall writing performance. It was discovered that students' quality of written products was improved in general. It was also discovered that students benefited the most from giving remarks to their peers' writing. The revision patterns of high, medium and low language ability students were also compared. It was found that the higher the language ability of the students, the more concerned they were with macro level for their revisions. ICT-mediated process writing has not garnered much attention in the field of CSL. The study hopes to contribute to the literature of ICT-mediated writing instruction in the field of CSL.