Adiponectin is known to play an important role in the regulation of blood glucose levels through the mediation of adiponectin receptors 1 and 2 (AR1 and AR2, respectively). The purpose of this study was to investigate the role of adiponectin in dental pulp cells. The expressions of both AR1 and AR2 were observed in dental pulp by reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting. Quantitative analysis of Alizarin Red S staining showed that 10 μg/mL of adiponectin significantly promoted mineralization by 1.6 times compared with control on day 12. However, no significant difference in mineralization was observed between control and 0.1 or 1 μg/mL adiponectin treatment. Moreover, real-time PCR results indicated that adiponectin (10 μg/mL) significantly increased the expression of dentin sialophosphoprotein (DSPP) by 2.3 and 1.8 times compared with control on days 8 and 12, respectively. These results indicated that adiponectin might promote mineralization by inducing DSPP expression in dental pulp cells.