Primary tumours of the trachea can be benign or malignant and account for fewer than 0·1% of tumours. However, they are a diagnostic and therapeutic challenge. Benign tumours are usually misdiagnosed as asthma or chronic lung disease, and can delay diagnosis for months or years. Because of their rapid growth and onset of haemoptysis, malignant tumours are often diagnosed earlier than benign tumours and patients thus often present with locally advanced disease. Inappropriate treatment is an equally frustrating issue. Modern techniques for tracheal surgery—laryngotracheal, tracheal, or carinal resection—combined with radiotherapy, can be offered curatively with low perioperative risks. Nevertheless, the low numbers of patients undergoing resection and the associated poor survival in epidemiological studies over the past two decades have shown that surgery is rarely considered outside referral centres, with radiotherapy or another form of local treatment (eg, endotracheal stents, debridement, brachytherapy) generally preferred. The liberal use of these other techniques should be avoided because surgery has the potential to cure all patients with benign and low-grade tumours and most patients with malignant primary tracheal tumours, and other techniques are usually palliative at best.