Periodontitis is a complex immune-inflammatory disease, characterized by the destruction of the periodontium. Periodontal regeneration implicates the use of mesenchymal stem cell populations for cell-based therapies. Periodontal ligament stem cells (PLSCs) isolated from the periodontal (PDL) tissue of human teeth, are the most extensively studied and applied for regeneration of the periodontal tissues. Platelet rich plasma (PRP) is widely used for various tissue engineering applications, because of its several advantages over fetal bovine serum (FBS). In this study, we isolated PLSCs from four extracted sound wisdom teeth. Venous blood was drawn from healthy male and activated PRP was prepared. The effect of various concentrations of human PRP (hPRP) in comparison with 10% FBS on PLSCs proliferation and osteogenic differentiation have been detected. Statistical analysis was done using a One-way analysis of variance (ANOVA). Our study showed that hPRP can effectively induce hPLSC's proliferation as well as stimulate osteogenic differentiation of hPLSC's. The 10% hPRP had the highest proliferation rate than 5% hPRP, 15% hPRP as well as 10% FBS with statistical significance at 3 and 5 days' groups. The RT-PCR showed that osteopontin gene in 10% FBS expressed higher than all PRP groups with no statistical significance and the osteopontin gene expression in the 10% hPRP group was higher than the 5% PRP and 15% PRP with no statistical significance.