Single-use supraglottic airway devices are now available and are intended to be comparable with the reusable LMA Classic laryngeal mask airway. We performed a randomised cross-over study comparing the Ambu AuraOnce Laryngeal Mask with the LMA Classic. Fifty patients participated in the trial. Success rates for insertion at the first attempt were similar (92% with the Ambu and 84% with the LMA Classic; p = 0.22). The volumes of air required to inflate the cuff to produce a seal were similar, but the cuff pressure was lower for the Ambu Laryngeal Mask (median (IQR [range]) 18 (10-31 [0-100] cmH(2)O) than the LMA Classic 27 (17-50 [4-90] cmH(2)O; p = 0.007). Visual analogue scores for ease of insertion were 87 (73-93 [26-97]) mm for the Ambu and 84 (60-89 [18-96]) for the LMA Classic (p = 0.017). Complications were similar in both groups. We suggest that the disposable Ambu Laryngeal Mask is an acceptable alternative to the reusable LMA Classic.