At the end of 19th century William Coley, a New York surgeon, was the first to describe necrosis of the tumour induced by bacterial toxins. In 1975, a protein responsible for the induction of this process was identified and called tumor necrosis factor alpha (TNF-alpha). The application of recombinant DNA methodology has resulted in the production of large quantities of highly purified recombinant human TNF-alpha for both preclinical and clinical studies. Although TNF-alpha is still viewed by most investigators as a selective antitumor agent, its pleiotropic activities are admirably illustrated by numerous newly discovered functions of TNF-alpha in the host defenses, inflammation, pathogenesis, regulation of gene expression and differentiation. This literature survey discusses the discovery of TNF-alpha and its potential applications to antitumour therapy.