Top-level research on Physiology of Yeasts and Filamentous Fungi is published in two FEMS journals, FEMS Yeast Research and FEMS Microbiology Letters, and some of the best representative papers from the two journals were collected in this joint virtual issue. We hope you will enjoy reading these exciting papers and consider submitting your discoveries on the Physiology of Yeasts and Filamentous Fungi to these journals in the near future.