This study was designed to evaluate the effect of LLLT on odontoblast-like cells derived from human bone marrow mesenchymal stem cells.40 fasks of odontoblast-like cells were obtained from 10 samples of h-BMMSCs and divided into 2 groups; control group (A) and diode laser (GaAlAs) irradiated group (B). Each group was further subdivided into 2 subgroups, where subgroups A1, B1 and A2, B2 were examined after 3 and 14 days after odontoblastic differentiation respectively. Each group was examined by inverted phase contrast light microscope to examine cell count and viability as well as alizarin red stained mineralized matrix.RT-PCR was performed for each subgroup to detect, the amount of gene expression of DMP1 and ALP. The data of cell count and RT-PCR were statistically analyzed. Conclusion: LLLT enhanced DMP1 and ALP gene expression, cell proliferation and matrix mineralization in odontoblast-like cells derived from h-BMMSCs.