The origin of the vascular Smooth Muscle Cell (SMC) involved with vascular remodelling is very controversial. The theory that SMCs can dedifferentiate is long standing. However, in more recent years this idea has been challenged with the emergence of resident progenitor stem cells in the vascular wall. Here, a population of primary Multipotent Vascular Stem Cells (MVSCs) were isolated using explant culture from the medial layer of rat aortic tissue. MVSCs were characterised for multipotency based on expression of neural crest markers Sox10, Sox17 and glia cell marker S100β. The cells were also characterised for their mesenchymal stem cell (MSC) like properties through their ability to differentiate into adipocytes and osteocytes and expression of markers CD44 and CD29. In maintenance media, the cells displayed a SMA+/CNN+/SM-MHCII- phenotype. After TGFβ1 and PDGF-BB stimulation the cells presented a SMA+/CNN+/SM-MHCII+ phenotype demonstrating their transition to SMCs. A10 and A7r5 cell lines are derived from the thoracic aorta of rat embryos. They are used widely as a model for non-differentiated neonatal and neointimal vascular SMCs. The discovery of resident MVSCs in the cell wall prompted the evaluation of these embryonic lines in relation to MVSC markers [Sox10, Sox17, S100β]. These cells expressed all three MVSC markers while concomitantly expressing SMA, CNN1 and SM-MHCII. Upon serum deprivation both cell lines had increased SMA and CNN1 expression. Both cell lines showed some potential to differentiate into adipocytes. Adult SMC lines from three different sources (bovine, rat and murine) were screened for MVSC markers and were found to express all three markers along with SMC markers SMA, CNN1 and SM-MHCII. However, these cell lines did not give rise to adipocytes or osteocytes after stimulation with induction media. These results indicate that a population of resident progenitors do exist in the vessel wall and may contribute to vascular remodelling after injury. The expression of MVSC markers in A10, A7r5 and various SMC lines indicates that these cells still retain some of their stem cell like properties and may not be terminally differentiated as previously described. NE4C neural stem cells were analysed for their SMC differentiation capabilities. The cells show some potential as a model for MVSC to SMC after TGFβ1 stimulation but further experiments are required to conclude these results.