Degree of tumour differentiation as a prognostic factor in advanced laryngeal cancer. As part of a retrospective analysis on treatment results in 139 patients with advanced laryngeal squamous cell carcinoma (T3-4) differentiation grade of the tumour was analyzed as a prognostic factor. Univariate analysis differentiation grade was related to tumour size, presence of neck node metastasis and conversion of N-stage during follow-up. For statistical analysis, patients with G1-G2 and G3-G4 were grouped. Prognosis for G3-G4 carcinomas is significantly worse for disease specific survival (p < 0.025), due to significantly more regional recurrence (p = 0.05). At multivariate analysis it turned out that regional control and disease specific survival in patients with no palpable neck nodes were adversely affected by the histological degree of differentiation of the diagnostic biopsy. For this group of patients extensive treatment of neck nodes is recommended.