Dental pulp stem cells (DPSCs) hold great promise for tooth regeneration and dental diseases. To expand the source of DPSCs and explore the feasibility of allogeneic usefulness of DPSCs, we investigated its immunogenicity and its immunomodulatory effects on T lymphocytes. The results showed that DPSCs failed to stimulate allogeneic T-cell proliferation. In addition, they significantly inhibited phytohemagglutinin-triggered T-cell proliferation and one-way mixed lymphocytes reactions. Soluble factor(s) may play important role in the immunosuppressive process. DPSCs have low immunogenicity and immunomodulatory actions on T lymphocytes, which may expand the source of DPSCs and reinforce the therapeutic interest in DPSCs.