The single tapered dilator kit is the most commonly used percutaneous tracheostomy set in the UK. The Cook Blue Rhino and the Portex Ultraperc were compared in the laboratory on mannequin and porcine airway models. The following data were collected: the subjective ease of dilating the trachea and inserting the tracheostomy tube; the time taken and the anterior-posterior compression during dilatation and tube insertion; the incidence and extent of posterior tracheal wall damage. During dilatation, the Blue Rhino caused less mean percentage anterior-posterior compression (34.8% vs. 51.5%, p = 0.0014). There was no difference in subjective ease or time for dilatation in either mannequin or porcine airway models. During insertion of the tracheostomy tube, the Ultraperc was subjectively easier in the porcine airway model (p = 0.001); had a shorter median insertion time in both the mannequin (3 s vs. 7.2 s, p = 0.0006) and the porcine airway model (4.3 s vs. 8.5 s, p = 0.0005); the mean percentage anterior-posterior compression caused was less in the mannequin (51.5% vs. 76%, p = 0.0008). The overall incidence of posterior wall damage was 65% with 25% having deep lacerations. There was no difference in the incidence of damage between the two sets. The Ultraperc therefore has advantages during tracheostomy tube insertion that are statistically and clinically significant. The advantages are probably due to the presence of the tracheostomy tube introducer.