Objective: In this study, the effects of the low intensity laser were evaluated in the proliferation of human dental pulp stem cells (DPSCs). Design: These cells were irradiated every 12 hours for 72 hours or at 0 and 48 hours only, with a Red-InGaAlP laser (660nm, 30mW and 0.5 or 1J/cm 2) for 16 or 33 seconds and their proliferation was assessed by the MTT assay. In addition, the Trypan Blue assay was used to analyze the viability of DPSCs in the best parameter recorded by MTT. Results: It was observed that the lowest dose of the laser (0.5J/cm 2) in applications at 0 and 48 hours obtained the higher proliferation rates then all the other groups. Finally, through the Trypan Blue assay, we observed that the viability of the stem cells was not affected by the low intensity laser (0.5J/cm 2). Conclusions: Our data corroborate with other data from the literature and therefore suggest that the low intensity laser can be used in order to improve cell proliferation. However, further studies should be carried out in order to evaluate if these parameters can be used in other cell lines.