This study investigated the causal relationship between cortical structure (surface area and thickness) and Alzheimer's disease (AD) risk using a bidirectional two-sample Mendelian randomization analysis. Suggestive associations were found between decreased surface area of the temporal pole and cuneus, and increased AD risk. Conversely, decreased surface area of the precentral and insular cingulate were suggestively associated with increased AD vulnerability. However, none of the Bonferroni-corrected p-values reached significance.