The internationalisation of higher education generates several issues related to quality, uniformity of subjects taught across campuses and the role of differences in English-speaking ability, which may affect student learning and skills development. This study used a self-assessment survey framework to investigate Australian (native English speaking) and Malaysian (non-native English speaking) students' perceptions of their writing-related competencies. These perceptions were then correlated with students' grades for specific writing tasks at the Australian and Malaysian campuses of Monash University, a research-intensive tertiary institution. Student perceptions of six competencies were determined upon commencement and completion of a core science subject, SCI2010. Australian and Malaysian student perceptions of their abilities improved for all six, and four of the surveyed competencies, respectively. Upon commencement of the science unit, Malaysian students' self-efficacy was higher than that of Australian students for three competencies. However, by completion, Australian students had higher self-efficacy for all six competencies, which correlated with their higher literature review grades. There was no difference in grades for the annotated bibliography assignment. These results have important implications for the delivery of university subjects across international campuses.