<p>This study draws on neo-institutional theory and the convergence/divergence debate in higher education research to examine whether public and private universities in EU candidate countries converge or diverge in their research activity and collaboration patterns. We analyse Scopus-indexed publication data for 43 universities across Albania, Bosnia and Herzegovina, Georgia, North Macedonia and Serbia for the period 2010–2022. The Wilcoxon signed-rank test was applied to assess significant differences between the two university groups. The blockmodelling procedure was applied to both non-normalised and normalised co-authorship networks of the universities to estimate the similarity of universities’ collaboration patterns. Our findings reveal that convergence and divergence operate simultaneously but at different analytical layers. At the surface layer of publication output and collaboration indicators, public and private universities are remarkably similar: they do not differ significantly in research productivity per person, share of high-quality output or international collaboration rates. At the structural layer of network positioning, however, private universities systematically occupy peripheral positions within national co-authorship networks, rarely collaborating with each other and mostly collaborating with one or two public universities. These findings suggest the convergence thesis: isomorphic pressures produce similar surface outputs but leave structural inequalities between sectors intact.</p>