Background: It has been established that periodontal ligament stem cells (PDLSCs) have a significant impact on restoration of periodontal tissues, and optimizing their differen-tiation into osteoblast is critical to improving clinical outcomes in periodontal regenera-tion. Different non-invasive method, including photobiomodulation (PBM) and vitamin D supplementation, hold potential for enhancing Osteoblastic Differentiation. the pres-ent work aimed at investigating the synergic impact of PBM by the use of a 980 nm di-ode laser and vitamin D on the osteogenic differentiation and cell viability of PDLSCs.<br /> Materials and Methods: Cultured PDLSCs were separated into six groups: 1. Control (no treatment), 2. Vitamin D, 3. PBM at 2 J/cm(2), 4. PBM at 2 J/cm(2)with Vitamin D (VD- 2 J/cm(2)), 5. PBM at 4 J/cm(2), and 6. PBM at 4 J/cm(2)with Vitamin D (VD- 4 J/cm(2)). We evaluated cell viability using the methyl thiazolyl tetrazolium assay at 24 and 72 hours post-irradiation. For the osteogenic differentiation assessment, we measured expression of osteogenic genes, including Runt-related transcription factor 2(RUNX2), Osteocalcin (OCN), alkaline phos-phatase (ALP), and Osteopontin(OPN), through quantitative reverse transcription-polymerase chain reaction. Additionally, Alizarin red staining was utilized for detecting calcification.<br /> Results: All study groups demonstrated enhanced viability in comparison with the control at both time intervals, with the exception of the vitamin D group at 72 hours. The PBM (4 J/cm(2)) and VD-2 J/cm(2) groups exhibited the highest levels of cell viability, respectively. All study groups exhibited increased expression of osteogenic genes in comparison with control group. The larg-est values were associated with groups that included both vitamin D and PBM. The calcification rate was markedly elevated in the VD-2 J/cm(2), VD-4 J/cm(2), and VD+OM groups, respectively.<br /> Conclusion: The integration of photobiomodulation with vitamin D has been shown to improve min-eralization and accelerate the osteogenic differentiation of PDLSCs, resulting in a synergistic effect.