Internationalisation for a higher education institution is defined as a process of integrating an international, intercultural, or global dimension into the teaching and learning, as well research activities. International co-authorship in research article is one of the means of collaboration towards internationalisation. Henceforth, this paper investigates the impact of international co-authorship of the research articles in the field of science, technology, engineering and mathematics (STEM) for a specialised young university (<50 years old) in Malaysia. The study focused on approximately 9450 article and the citations ranging from 2012-2017. The impact due to annual article publication, annual citation count, most cited article, annual citation per article and the correlation between the publication and citation were analysed. The finding shows that faculty members of the university have been collaborated with authors from 86 countries since 1997, which dominated by Asian institutions. From the results, annual citation per article (Cpp) showed that collaborations with European countries brought highest impact for the mean Cpp. Meanwhile, the analysis on the cumulative citation trend illustrated that the citation count is proportional to the number of articles, which proves that international co-authorship does impacts STEM specialised young university. © 2019, DESIDOC.