Hepatocyte growth factor (HGF) is a multifunctional factor which promotes proliferation, motility and morphogenesis in epithelial cells. In addition, it has been found to play an important role in cartilage metabolism. To investigate articular cartilage repair using HGF in vivo, we injected HGF into rabbit knee joints, where 4 mm diameter osteochondral defects had been made, and observed the animals for 6 months. We found that HGF effectively repaired osteochondral defects. The repair process of the articular cartilage defects using HGF was shown to be much better than saline injection on all macroscopic and histologic examinations. Although the observation period in our study was short, HGF is one of the most promising candidates for repairing articular cartilage defects clinically.