This work developed a three-dimensional (3D) diffusion-prepared segmented steady-steady free precession (DP-SSFP) cardiovascular magnetic resonance (CMR) sequence for black-blood (BB) thoracic aortic and carotid wall visualization. In 14 healthy volunteers, BB CMR of the thoracic aorta (n = 7) and carotid arteries (n = 7) was performed over 12 cm and 3 cm of transversal coverage, respectively, with a single 3D DP-SSFP acquisition and multiple two-dimensional (2D) slices using a T2-weighted (T2W) double inversion-recovery fast spin-echo (DIR-FSE) sequence. Arterial wall area (WA), lumen area (LA), and wall-lumen contrast-to-noise ratio (CNR) measured from the 3D DP-SSFP images were compared to those measured from the 2D T2W DIR-FSE images. Strong agreement in WA and LA between the two techniques was observed in the thoracic aorta (WA: intraclass correlation coefficient (ICC) = 0.866, LA: ICC = 0.993; p < 0.001 for both) and carotid arteries (WA: ICC = 0.939, LA: ICC = 0.991; p < 0.001 for both). Adjusted for slice thickness and number of slices, higher effective CNR per unit time (i.e., CNR efficiency) was attained with 3D DP-SSFP than 2D T2W DIR-FSE during thoracic aortic wall imaging (11.6 +/- 1.4 vs. 2.9 +/- 0.5; p < 0.001) and carotid artery wall imaging (10.1 +/- 1.9 vs. 3.1 +/- 0.5; p < 0.001). Diffusion-prepared segmented SSFP is a promising vessel wall CMR sequence that allows for 3D acquisition of thin and contiguous slices with BB image contrast.