COVID-19 still remains a severe global health threat. Despite the high-speed development of vaccines that efficiently prevent COVID-19, there are still no effective treatments of the disease once people are infected. MicroRNAs are powerful regulators of gene expression. They are intensely investigated as therapeutic targets up to the clinical stage. In addition, microRNAs can be detected in the circulation, and thus, represent promising diagnostic and prognostic biomarkers for (long)-COVID-19. © Die Autoren 2021.