Vascular smooth muscle cells (SMC) in the ascending thoracic aorta arise from neural crest cells, whereas SMCs in the descending aorta are derived from the presomitic mesoderm. SMCs play important roles in cardiovascular development and aortic aneurysm formation. This protocol describes the detailed process for explanting ascending and descending SMCs from mouse aortic tissue. Conditions for maintenance and subculture of isolated SMCs and characterization of the vascular SMC phenotype are also described.