The scans of 120 patients with proven head and neck cancer who underwent magnetic resonance imaging (MRI) at Mt. Vernon hospital were reviewed and, where possible, compared with their clinical, computed tomography (CT) and histological findings. MRI was generally superior to both clinical examination and CT in the detection of cervical lymphadenopathy and in the assessment of primary tumour extent, particularly in the tongue base, nasopharynx and parotid gland. Small intracranial tumour extensions were more readily detected by MRI than CT. MRI was no better than CT in distinguishing between malignant and inflamed tissues and was generally inferior to CT in spatial resolution, patient acceptance and examination cost.