Indonesia is home to a high number of Critically Endangered land vertebrates. Examining the research on these species is important to improve biodiversity-related policy and management and to provide insight into knowledge gaps. We conducted a comprehensive review of 2,188 publications published during 2000–2021 that studied the Critically Endangered vertebrate species of Indonesia, to understand variations in the level of research on each species and the proportion of research carried out within Indonesia and by Indonesian researchers. Over this 22-year period, research on Critically Endangered species in Indonesia increased, but > 50% of this research was carried out by researchers based outside Indonesia. Moreover, the quantity of research was uneven across taxonomic classes, indicating an imbalance in research attention. Most publications during the period were on mammals (1,573 publications), followed by reptiles (310), birds (300) and amphibians (5). We identified 17 species for which there were no significant publications, suggesting little attention has been given to these species. We highlight three key issues: limited Indonesian authorship, taxonomic bias towards mammals and birds, and a need to address these challenges in authorship and bias. The low number of publications on many Critically Endangered land vertebrates reflects a lack of research effort, mostly because of limited funds and unequal conservation attention.