We quantitated c-myc oncoprotein in 44 squamous cell carcinomas of the head and neck using an enzyme-linked immunosorbence assay. The clinicopathological parameters of these patients were followed up for between 3 and 60 months and analysed for any correlations with observed levels of c-myc protein using the Kruskal-Wallis one-way analysis of variance method. Although no statistical correlation was found between different clinicopathological parameters (patient age, sex, TNM staging, number of lymph nodes invaded, extracapsular rupture of the tumour, its histopathological differentiation, or its site), the survival periods of patients with tumours possessing elevated levels of c-myc protein were found to be statistically shorter than those with lower levels of c-myc expression, (P less than 0.02). This indicates that c-myc expression may be an effective prognostic indicator in head and neck cancer.