A blood supply is crucial for tissue healing and regeneration. Periodontal ligament (PDL) tissue is situated between the tooth root and alveolar bone, and cells derived from PDL tissue are reported to have stem cell-like activity. This study aimed to evaluate the potential of PDL cells derived from deciduous teeth to express endothelial cell (EC)-specific markers. Using quantitative PCR, we investigated whether PDL cells derived from human deciduous teeth express mRNA for the EC-specific markers: vascular endothelialcadherin (VE-cadherin), vascular endothelial growth factor receptor 2 (VEGFR2) and CD31 upon treatment with 15 ng/ml heparin or 10 ng/ml fibroblast growth factor (FGF)-2 in vitro. Quantitative PCR showed that PDL cells expressed mRNA for the EC-specific markers, VE-cadherin and VEGFR2, when cultured in the presence of heparin alone or with FGF-2. By contrast, marked CD31 mRNA expression was induced only when PDL cells were cultured with both heparin and FGF-2. Western blot analysis showed that the CD31 protein was induced in PDL cells upon treatment with both heparin and FGF-2 for 3 weeks. PDL cells derived from deciduous teeth inducibly express EC-specific markers and thus have the potential to differentiate into a vascular cell lineage.