Since tracheal cannulas are increasingly used to wean intensive-care patients from respiratory machines, more doctors and nurses will find themselves having to take care of patients with tracheostomas. Indications for tracheal cannula use include the likelihood of prolonged mechanical ventilation and/or difficult weaning. Percutaneous dilatational tracheotomy is a relatively simple procedure for inserting a tracheal cannula. It is performed using a modified Seldinger technique, carried out under general anaesthesia; use of a bronchoscope during the operation makes the procedure simpler and safer. When it is difficult to pinpoint the source of problems arising in patients fitted with a tracheal cannula, it must always be considered that the cannula might be the cause. Although rare, complications may arise several weeks or months after decanulation, such as stenosis of the trachea, changes in voice and fistula formation between the trachea and skin. A strict surveillance protocol is needed to recognize and treat late complication.