English language learners today have considerable opportunities to practice their writing skill via their peer interaction in Web 2.0 platforms, such as Blogs, Wikis, and Google Docs. Different studies have investigated the influence of these platforms on student writing collaboration and interaction, but few studies had explored factors that may affect English for Specific Purposes (ESP) student collaborative writing in Vietnamese settings. This study, therefore, attempts to explore the impact of four factors, namely gender, student attitudes towards learning English, student economic status, and availability of English at home on Google Docs-based interaction and collaborative writing outcome at a southern university in Vietnam. Fifty participants took part in this study and they worked collaboratively in small groups in Google Docs to finish two writing tasks and complete a survey afterwards. Analysis of their survey, interaction, and writing outcome suggests that gender, student attitudes towards learning English, and the number of books available at their homes have an impact on their writing outcome whereas their economic status did not seemingly affect their writing quality. Some pertinent pedagogical implications are also discussed in this paper. Keywords: Google Docs, collaborative writing, English for Specific Purposes DOI: 10.7176/JLLL/78-02 Publication date: April 30th 202