The effects of low-level laser therapy (LLLT) has been the focus of recent studies as being assumed responsible for promoting photostimulatory and photobiomodulatory effects in vivo and in vitro, increasing cell metabolism, improving cell regeneration and invoking an anti-inflammatory response. A positive effect of LLLT on the bone proliferation of some cell types has been observed, but little is known about its effect on dental pulp stem cells (DPSCs). Here, we accurately describe the technical procedure to isolate mesenchymal DPSCs, and assay their osteogenic capacity when irradiated with an LLLT source. These preliminary results show that LLLT irradiation influences the in vitro proliferation of DPSCs and increases the expression of essential proteins for bone formation, although it is necessary to carry out further experiments on other cell types and to uniform the methodological designs.