Purpose: The purpose of this paper is to report on an investigation of university students' participation and learning presence in a blogging activity, designed to support collaborative learning. There are three main reasons justifying the current research: to better understand the structure and the dynamics of students' blogging subgroups; to reveal students' patterns of engagement and their roles within the blogging community; and to evaluate the applicability of social network analysis (SNA) in studying students' performance and learning presence in educational blogs. Design/methodology/approach: The design of students' blogging activities was rooted on the ideas of authentic learning and followed a project-based learning philosophy. Data analysis used methods of SNA to reveal collaborative aspects of students' engagement, the different roles undertaken by the students and the structure of the community within group blogs. Findings: SNA shed light into the different patterns of students' participation and the dynamics of students' learning presence within the community of group blogs. Research findings, both quantitative and qualitative, indicated that the majority of the students in the sample were generally active and exhibited learning presence actions within their group blog. Differences between students in the various groups were also recorded. Research limitations/implications: The study reported here is limited by the specific sample and the context of implementation. Future research will be directed towards applying the Community of Inquiry schema, in a way complimentary to SNA, to further analyse students' learning and cognitive presence in the community of the whole blogging project. Originality/value: The originality of the paper concerns both the educational design of the blog-based project activities and the use of SNA to reveal the different patterns of students' participation in educational blogging activities. Results could be of value for both educators and researchers in the field. (Contains 4 tables and 5 figures.)