Background: Trichosporon dohaense  is a rare fungal species that has not been described in human invasive infections. 
Patients and methods: In this study, we investigated two T. dohaense  isolates from patients with invasive infections in two hospitals in China, as part of the China Hospital Invasive Fungal Surveillance Net (CHIF-NET) program. Both patients were under immunocompromised conditions. 
Results: On chromogenic agar, T. dohaense  isolates were dark blue, similar to the color of Candida. tropicalis , but the characteristic moist colony appearance was quite different from that of T. asahii . The two isolates were misidentified as T. asahii  and T. inkin  by the VITEK 2 YST system. The rDNA internal transcribed spacer (ITS) region and the D1/D2 domain sequences of the two T. dohaense  isolates were 100% identical to T. dohaense  type strain CBS10761^T. The sequence of the intergenic spacer region-1 also clearly distinguished the species. Of the three matrix-assisted laser desorption/ionization time-of-flight mass spectrometry systems, Bruker Biotyper and Autobio MS correctly identified the two isolates to species level, whereas Vitek MS systems misidentified them as T. ovoides  or T. asteroides . Echinocandins exhibited no in vitro activities against the two T. dohaense  isolates. In addition, the isolates exhibited intermediate susceptibility to fluconazole (with minimal inhibitory concentrations [MICs] of 8 and 16 µg/mL) and itraconazole, voriconazole, and posaconazole (MICs of 0.25–1 µg/mL). T. dohaense  demonstrated susceptibility to amphotericin B with MIC of 1 µg/mL. The MICs of fluconazole and voriconazole in our study were higher than the MIC₅₀ of 62 for T. asahii  isolates (4 and 0.064 µg/mL) in the CHIF-NET program. 
Conclusion: This case study points to a possible emergence of T. dohaense  as an opportunistic human invasive fungal pathogen, and the reduced susceptibility should be noted.
Keywords: Trichosporon dohaense , invasive infection, emerging pathogen, identification, reduced susceptibility