['To investigate the expression of alpha, beta, and gamma catenins in oropharyngeal and hypopharyngeal squamous cell carcinoma and their relations to each other, as well as to clinical data, tumour differentiation, and prognosis.', 'Primary tumours for analysis were obtained from 138 patients diagnosed with squamous cell carcinoma of the oropharynx or hypopharynx between 1975 and 1998 in eastern Finland. Immunohistochemistry was used to evaluate the expression of alpha, beta, and gamma catenins. The expression patterns of all catenins were related to clinical data and survival.', 'The expression patterns of all three catenins were significantly interrelated. Reduced gamma catenin expression was significantly associated with poor histological differentiation. No association was found between alpha or beta catenin expression and clinicopathological characteristics. In univariate analysis, patients whose tumours had nuclear beta catenin expression had shorter overall survival than patients with no nuclear expression. In Cox multivariate analysis, nuclear beta catenin expression, tumour status (T class), and Karnofsky performance index were independent prognostic factors of overall survival.'] Is nuclear beta catenin expression related to unfavourable outcome in oropharyngeal and hypopharyngeal squamous cell carcinoma?