BACKGROUND: Presepsin is a widely recognized biomarker for sepsis. However, little is known about the usefulness of presepsin in invasive fungal infection. The aim of this study was to determine the plasma levels of presepsin in fungal bloodstream infections and to investigate whether it reflects the disease severity, similar to its utility in bacterial infections. METHODS: We prospectively measured presepsin in plasma samples from participants with fungemia from April 2016 to December 2017. The associations of C-reactive protein, procalcitonin, and presepsin concentrations with the severity of fungemia were statistically analyzed. In vitro assay was performed by incubating Escherichia coli, Candida albicans, and lipopolysaccharide to whole blood cells collected from healthy subjects; after 3 h, the presepsin concentration was measured in the supernatant and was compared among the bacteria, fungi, and LPS groups. RESULTS: Presepsin was increased in 11 patients with fungal bloodstream infections. Serial measurement of presepsin levels demonstrated a prompt decrease in 7 patients in whom treatment was effective, but no decrease or further increase in the patients with poor improvement. Additionally, presepsin concentrations were significantly correlated with the Sequential Organ Failure Assessment score (r = 0.89, p < 0.001). In vitro assay with co-incubation of C. albicans and human whole blood cells indicated that the viable cells of C. albicans caused an increase in presepsin, as seen with E. coli. CONCLUSIONS: Plasma presepsin levels increased in patients with fungal bloodstream infection, with positive association with the disease severity. Presepsin could be a useful biomarker of sepsis secondary to fungal infections.