Although statistics for cancer of the larynx are reported according to the tumor, node, metastasis (TNM) morphological staging system, functional clinical distinctions can identify major prognostic differences within the same morphological stage. This study was done to improve the staging system by incorporating pertinent clinical variables. In 193 patients with cancer of the larynx first treated between 1973 and 1985, the total 5-year survival was 66% (127/193). By TNM stage it was I, 78% (60/77); II, 67% (32/48); III, 60% (27/45); and IV, 35% (8/23). In three new functional severity stages that combined symptom severity and comorbidity, the corresponding rates were alpha, 83% (89/107); beta, 58% (34/59); and gamma, 15% (4/27). The functional severity stages could be combined with TNM stages to create a powerful new clinical severity staging system, in which the survival results were A, 88% (53/60); B, 80% (24/30); C, 63% (38/60); and D, 28% (12/43). These results demonstrate that inclusion of clinical variables in a formal staging system can strikingly improve prognostic estimations and classification of patients.