Hepatocyte growth factor (HGF), otherwise known as scatter factor (SF), has been demonstrated over the past decade to elicit a number of functions that may be tumorigenic, and enhance the invasive/metastatic nature of cancer cells. Clinical studies have also demonstrated that HGF/SF, together with its receptor, cMET, is closely related to the disease progression and prognosis of patients with cancer. The past few years have seen the identification of numerous inhibitors and antagonists to the action of HGF/SF. These factors have demonstrated a possible role in minimising the action of HGF/SF on cancer cells, and may be of therapeutic value in the future. This article overviews the activators, inhibitors, and antagonists to HGF/SF and discusses the possible implications in cancer therapy.