Paranasal sinus cancers are rare, aggressive tumours that are usually diagnosed at an advanced stage. They differ from other upper aerodigestive tract tumours in terms of risk factors (wood dust exposure) and premalignant lesions (inverted papillomas). The diagnosis should be suspected in the presence of unilateral and continuous nasal sinus symptoms or bone lysis or a heterogeneous opacity on imaging. The definitive positive diagnosis is based on histological examination. Staging must comprise face, brain, neck and chest CT as well as face and brain MRI. Tumours are stage T3-T4 in two-thirds of cases and are associated with cervical lymph node involvement in 10% of squamous cell carcinomas and 4% of adenocarcinomas. These tumours must be managed in reference centres experienced in all of the various treatment modalities. Treatment decisions must be based on a multidisciplinary approach comprising local, regional and national REFCOR expertise (French rare head and neck cancer network). Optimal treatment is surgical resection with clear margins associated with adjuvant intensity-modulated radiotherapy (IMRT). Although it has been improved over recent decades, the prognosis remains poor with local recurrences occurring in 38% of cases and a five-year overall survival of about 63%.