The aim of this paper is to investigate the common genetic influence on the cortical thickness (CT) and white matter (WM) connectivity. To this aim, we analyzed cortical gray matter (GM) thickness derived from structural magnetic resonance images and the measures of WM connected to the cortex obtained from diffusion magnetic resonance imaging (dMRI) on a large twin imaging cohort (N = 308, average age 22.8 ± 2.3 SD). The CT was estimated using a surface-based approach, and the WM connections were measured based on probabilistic tractography using fiber orientation distributions (FODs) from dMRI. Bivariate genetic modeling was performed on CT and FOD measure of tracts connected to the cortex. Significant genetic correlations between the CT and WM connectivity were found in regions, including the right postcentral gyrus, left posterior cingulated gyrus, right dorsolateral superior frontal gyrus, the right middle, and inferior temporal gyri, suggesting common genetic factors influencing the GM and WM.