BACKGROUND: People living in rural areas have poorer health than their urban counterparts. Although rural health research centres have been promoted as vehicles for improving rural health by contributing evidence to address rural health disadvantage and building research capacity, their characteristics and evolution are poorly understood. Collaboration is known to have an important positive influence on research outputs and research quality. In this study we examine publication outputs from an Australian rural research centre to evaluate how researchers have engaged in research collaboration over a two-decade period. METHODS: A retrospective longitudinal study of publications in peer-reviewed journals from a rural research centre-University Centre for Rural Health (UCRH) -between January 2002 and December 2021. Organisational co-author networks across four periods (2002-2006; 2007-2011; 2012-2016; 2017-2021) were constructed based on author organisational affiliations and examined using social network analysis methods. Descriptive characteristics included organisation types, study design, region of study focus, thematic research trends, Aboriginal and Torres Strait Islander and female authorship, and journal characteristics. RESULTS: We identified 577 publications with 130 different UCRH-affiliated authors. Publications and the co-author network increased in number and diversity over each period, with an acceleration and a consolidation of the network in the final period. Over time there was an increase in publications related to Aboriginal and Torres Strait Islander health, coupled with an increase in Aboriginal and Torres Strait Islander authorship and collaborations with Aboriginal and Torres Strait Islander organisations; rise in female senior authorship and publication in quartile 1 journals. About two-thirds of publications make no reference to regional or remote populations. CONCLUSION: Collaboration in publications increased, expanded, and consolidated, which coincided with an increase in the number and diversity of both co-authoring organisations and UCRH-affiliated authors in the final period. The findings highlight the value of collaborations (including urban and international) in building and strengthening rural health research capacity. With increased capacity and consolidation of the network it is now imperative that research becomes more focussed on understanding and addressing rural health inequities.