Objective:To investigate tau distribution in patients with corticobasal syndrome (CBS) using ¹⁸F-AV-1451 PET.Methods:Six consecutively recruited patients with CBS and 20 age-matched healthy controls underwent 2 PET scans with ¹⁸F-AV-1451 (for tau) and ¹⁸F-florbetaben (for β-amyloid). We compared standardized uptake value ratio maps of the ¹⁸F-AV-1451 PET images between the patients with CBS and controls.Results:Compared to controls, patients with CBS exhibited asymmetrically increased ¹⁸F-AV-1451 binding in the putamen, globus pallidus, and thalamus contralateral to the clinically more affected side and in the ipsilateral globus pallidus and dentate nucleus. Voxel-based comparison additionally showed asymmetrically increased ¹⁸F-AV-1451 binding in the focal regions of the precentral gray and white matter and in the midbrain, predominantly in the contralateral side. ¹⁸F-AV-1451 binding in the precentral white matter correlated with motor severity.Conclusions:¹⁸F-AV-1451 asymmetrically binds to motor-related subcortical gray and white matter structures in patients with CBS. This pattern corresponds to tau pathology distribution in postmortem studies, and motor deficit in patients with CBS may be associated with tau accumulation predominantly in the subcortical white matter underlying the motor cortex, leading to disruptions in motor-related networks.