The aim of the study was to analyse the clinical outcome of patients treated surgically for oral carcinoma. A retrospective cohort study was undertaken of 356 patients with oral cavity cancer whose clinicopathological information had been collected prospectively onto a dedicated head and neck database. Disease recurrence and survival were assessed. Neck metastases occurred in 42% of patients. Tumour thickness (both 2 and 5 mm) predicted the presence of nodal metastases. Both pathological T stage (P < 0.001) and tumour thickness cut-off of 5 mm (P = 0.03) were independent predictors of disease-specific survival. With a median follow up of 41 months, overall survival at 5 years was 59% and disease-specific survival was 73%. Patients with thick tumours have a high risk of nodal metastases and this supports the liberal use of elective selective neck dissection in patients with clinically negative necks.