The role of the immune system in the pathogenesis and treatment of cancer is currently a popular area of research. An underlying fundamental concept of cancer immunology is the supposition that tumor cells express antigens differently than normal cells, both qualitatively and quantitatively. Understanding tumor-host interactions may suggest opportunities to modify these relationships to obtain antitumor effects. There is growing evidence that the immune system plays an important role in the pathogenesis of squamous cell carcinoma of the head and neck (SCCHN). Based on this evidence, trials studying the therapeutic efficacy of biologic response modifiers (BRMs) have been undertaken. These trials have had variable success, but continued efforts incorporating newer cytokines are underway.