Autologous chondrocyte transplantation (ACT) is an established method in cartilage repair. Although long-term results show durable repair of isolated cartilage defects, some problems still remain. Since hypertrophy of the transplanted periosteum is a common problem, alternatives for periosteum are in demand. Periosteal grafts have been reported to stimulate neochondrogenesis via paracrine effects. The objective of this study was to evaluate the modulation of chondrocyte metabolism by periosteal grafts in vitro.