Head and neck surgery may be complicated by penetration of the dura resulting in meningitis, cerebrospinal rhinorrhoea, cerebral abscess or other intracranial complications. The strength of the dura mater both protects the brain and spinal cord and makes dura an ideal material for grafting (when needed). This study examines the thickness and histological composition of dura mater at various sites encountered in head and neck surgery. Dura was removed from eight specified locations in 14 adult cadavers. Microscopically, this dura was found to consist predominantly of collagen fibres, although the thickness of the dura varied between sites. Dura was significantly thinner in relation to the ethmoid sinus (P less than 0.01), tegmen (P less than 0.05) and sigmoid sinus (P less than 0.001), indicating its greater susceptibility to possible injury at these sites during surgery. The variety of its thickness also makes dura a more versatile homograft material than hitherto realised.