The purpose of this study was to investigate the effects of Fibrin Glue (FG) and activated platelet-rich plasma (a-PRP) on the proliferation and osteogenic differentiation of human dental pulp stem cells (h-DPSCs). Therefore, we planned to investigate in vitro behavior of porous composite scaffolds based on chitosan-gelatin/nanohydroxyapatite (CS–G/nHA) treated with FG and a-PRP. The porous structure of CS–G/nHA was prepared using combination of particle leaching and freeze-drying methods. The a-PRP was prepared from the centrifugation of whole blood activated with calcium chloride. Four groups of composite scaffolds were fabricated to seed h-DPSCs: (1) a-PRP–FG/CS–G/nHA; (2) FG/CS–G/nHA; (3) a-PRP/CS–G/nHA; (4) CS–G/nHA. The 14 days SEM image reveled organized fibrin network on scaffolds surface. All groups treated with FG and a-PRP, showed improved adhesion of seeded h-DPSCs compared to CS–G/nHA. Cytotoxicity of the composite scaffolds was assessed by MTT. Alizarin red staining confirmed the formation of bone minerals by h-DPSCs after 21 days of cell seeding. In addition, the a-PRP–FG treated scaffolds exhibited significantly elevated bone gamma-carboxyglutamic acid-containing protein (BGLAP), bone morphogenetic protein 2 (BMP2), and runt-related transcription factor 2 (RUNX2) gene expression. The present result the composite scaffolds treated with FG and a-PRP showed a fibrin network, preferentially on the surface of composite scaffold increasing the mineralization and osteoblastic differentiation of harvested cells. In addition, a-PRP–FG/ CS–G/nHA scaffold increased bone marker gene expressions from day 7 to day 21.