A recently developed imaging agent, technetium-99m (v) dimercaptosuccinic acid (99mTc (v) DMSA), has been used to assess head and neck squamous carcinoma (SCC). We have prospectively studied 62 patients of whom 53 had a histologically proven head and neck SCC. The remaining nine had benign lesions. The results of planar imaging in patients with primary disease yielded an 85% sensitivity and 78% specificity. Planar imaging in patients with cervical lymphadenopathy revealed a 59% sensitivity. Nineteen patients also had single photon emission computed tomography imaging which improved the image quality, spatial resolution and sensitivity of the investigation. Twenty-seven patients were scanned before and after radiotherapy and, of these, 96% showed positive uptake in the salivary glands with no evidence of tumor recurrence. This study has shown 99mTc (v) DMSA imaging provides a cheap and rapid method of investigating head and neck SCC and further studies are necessary to evaluate its role in the management of patients with this disease.