ObjectivesGlobal brain volume changes in patients with myelin oligodendrocyte glycoprotein antibody‐associated disease compared with healthy controls (HC) could be revealed by magnetic resonance imaging, but specific atrophy patterns of cortical structures and relation to cognitive impairment are not yet comprehensively known. Thus, we aimed to investigate cortical thickness differences in patients with myelin oligodendrocyte glycoprotein antibody‐associated disease compared with HC.Methods3‐Tesla brain magnetic resonance imaging was performed in 23 patients with myelin oligodendrocyte glycoprotein antibody‐associated disease and 49 HC for voxel‐wise group comparisons and neuropsychological testing in patients. Surface‐based morphometry with region of interest‐based surface analysis and region of interest‐based extraction of cortical thickness was performed in patients compared with HC and in patient subgroups with and without cognitive impairment.ResultsComparing patients with myelin oligodendrocyte glycoprotein antibody‐associated disease with HC, exploratory surface‐based morphometry demonstrated cortical volume reduction in pericalcarine and lingual cortical regions. Region of interest‐based surface analysis specified reduced cortical thickness in the adjacent pericalcarine and orbitofrontal regions in myelin oligodendrocyte glycoprotein antibody‐associated disease, as well as reduced temporal cortical thickness in patients with cognitive impairment (n = 10). Patients without cognitive impairment (n = 13) showed only circumscribed cortical brain volume loss compared with HC in the pericalcarine region.InterpretationIn conclusion, cortical atrophy in myelin oligodendrocyte glycoprotein antibody‐associated disease was characterized by cortical thickness reduction in the adjacent pericalcarine and orbitofrontal regions, with a tendency of temporal thickness reduction in cognitively impaired patients.