The need to mechanically characterize arterial tissues arises from the fact that arterial stiffness is a predictor of cardiovascular health problems. Recently, the atomic force microscope has been used in many studies on biological materials to image and perform quantitative mechanical analyses. In this study, the atomic force microscope was used to examine the variation in stiffness radially along a cross-section of porcine aorta, from the intimal to the adventicial layer. Force-Volume AFM mode was performed on both dry and hydrated cryosectioned (~10μm thick) specimens of aorta. Stiffness was defined as the change in indentation force of the loading portion of a force curve over the change in indentation depth. Stiffness and location data were normalized with respect to the AFM tip cantilever spring constant and cross-sectional radius, respectively. It was found that the stiffness of the aorta tissue showed no correlation with aortic radius (0.006 < R² < 0.023).