Academic writing in higher education involves acculturation of discourse characterised by new and unfamiliar social, cultural and academic conventions which remain a huge challenge for instructors and students worldwide. This study aimed at investigating the use of Blackboard Collaborated-Based Instruction to improve academic writing skills of second language writers. Drawing from Vygotsky's sociocultural framework, this study is premised on online collaborative writing tasks which encourage peer feedback and the exchange of ideas that gives sense of an audience larger than one consisting only of the teacher. Data were collected through metacognitive reflective interview of eight first-year students registered for a Bachelor of Education degree programme. The findings show that Blackboard Collaborated-Based Instruction provided second language writers with an online learning community in which they collaborate and help each other in editing, revising, and improving their academic essay through peer feedback. The findings also provide an insight into how learning academic writing skills is facilitated by scaffolding between peers wherein Blackboard Collaborated-Based Instruction serves as a mediator in students' development of academic writing.