Purpose: The purpose of this paper is to report results from an evaluation of an online abstract mentoring programme to support early career and less experienced human immunodeficiency virus (HIV) researchers improve their chances of acceptance to International HIV/Acquired Immunodeficiency Syndrome Conferences. Design/methodology/approach: An evaluation study was conducted on the impact of this programme over two conferences. Survey questionnaires also gathered data on the perceptions of users and mentors on the value of online mentoring. Findings: Results from the evaluation show that online mentoring increased the motivation and acceptance rate of early career and less experienced researchers, especially from low- and middle-income countries. Research limitations/implications: This study shows that the use of online mentoring at a distance can make access to desirable literacy practices for researchers' professional development more equitable, and enhance the added value of informal learning in today's lifelong learning context. It also shows a cost-effective way to use technology to widen participation of early career researchers from resource-limited settings, and improve their understanding of the practice of writing up and publishing research for competitive international conferences or journals. Practical implications: With a situated and constructivist view of online teaching and learning, the paper considers the implications for redesigning future global conferences as collaborative capacity-building spaces, via the use of Web 2.0 technologies. Originality/value: This paper provides research capacity builders with insights into the use of online mentoring to not only build writing skills, but also to enhance the induction of novices into a global learning community. It aims to inform decision makers of issues in effective online mentoring design to consider for impact and quality. (Contains 1 table and 4 figures.)