BACKGROUND: Anti-IgLON5 disease is a rare autoimmune neurological disorder with prominent Tau protein deposits in the brainstem and hypothalamus. The aim of this study was to visualize the in vivo distribution patterns of Tau protein in patients with anti-IgLON5 disease using the second-generation Tau PET tracer, Florzolotau (18F) PET imaging. METHODS: Patients diagnosed with anti-IgLON5 disease were enrolled consecutively. Age- and sex-matched healthy controls (HCs) were also enrolled. The uptake of Florzolotau (18F) and RESULTS: A total of 10 patients with anti-IgLON5 disease and 40 HCs were included in the study. All ten patients with anti-IgLON5 disease underwent Florzolotau (18F) PET scans, and five of them underwent CONCLUSIONS: This study indicates distinct Tau protein deposition patterns in patients with anti-IgLON5 disease, potentially serving as imaging biomarkers.