Twenty cases of head and neck mucosal squamous cell carcinoma containing a prominent sarcomatoid element were reviewed with special attention to possible prognostic factors. Patients whose tumors invaded muscle, minor salivary or accessory respiratory glands, or bone had very poor survival rates, whereas those whose tumors were superficial and did not extend into any of these structures had excellent survival rates. A history of irradiation to the tumor site and tumor location in the oral cavity rather than the larynx, pharynx, nasal cavity, or nasal-associated structures were associated with invasiveness and thus with poorer survival. Aside from invasion, histologic features and gross configuration were not found to be of significant prognostic importance.