This study was designed to investigate the biological effects of fish collagen peptide (FCP) on human osteoblasts. Human osteoblasts were treated with 0.1% FCP, which was the optimal concentration confirmed by the increase in alkaline phosphatase activity. After one, three, five and seven days of culture, the number of FCP-treated cells increased significantly compared with untreated cells. In a real-time PCR analysis, the expression of osteocalcin, osteopontin, BMP-2 and integrin β3 mRNAs in FCP-treated cells showed increases compared with untreated cells after three days of culture. After seven days of culture, the expression levels of osteopontin and integrin β3 were still higher in the FCP-treated cells than in untreated cells. The production of osteocalcin, osteopontin and integrin β3 proteins in FCP-treated cells also showed increases after seven days of culture. Furthermore, FCP accelerated matrix mineralization in the cultures. The present study indicates the potential utility of FCP as a biomaterial.