Introduction: A large number of COVID-19 publications has created a need to collect all research-related material in practical and reliable centralized databases. The aim of this study was to evaluate the functionality and quality of the compiled World Health Organisation COVID-19 database and compare it to Pubmed and Scopus. Methods: Article metadata for COVID-19 articles and articles on 8 specific topics related to COVID-19 was exported from the WHO global research database, Scopus and Pubmed. The analysis was conducted in R to investigate the number and overlapping of the articles between the databases and the missingness of values in the metadata. Results: The WHO database contains the largest number of COVID-19 related articles overall but retrieved the same number of articles on 8 specific topics as Scopus and Pubmed. Despite having the smallest number of exclusive articles overall, the highest number of exclusive articles on specific COVID-19 related topics was retrieved from the Scopus database. Further investigation revealed that PubMed and Scopus have more comprehensive structure than the WHO database, and less missing values in the categories searched by the information retrieval systems. Discussion: This study suggests that the WHO COVID-19 database, even though it is compiled from multiple databases, has a very simple and limited structure, and significant problems with data quality. As a consequence, relying on this database as a source of articles for systematic reviews or bibliometric analyses is undesirable.