LMA-Supreme (SLMA) is a new, single-use, latex-free, laryngeal mask airway with gastric access. The anatomically shaped airway tube permits easy insertion without placing fingers in the patient's mouth. The cuff is designed to provide higher seal pressures than the LMA-Classic or Unique. A prospective, randomized, cross-over study of LMA-Proseal (PLMA) and SLMA in 36 fasted, adult, female patients with general anaesthesia, neuromuscular block (NMB) and positive pressure ventilation (PPV) is presented. First attempt insertion in 35/36 patients in each group (two attempts in one PLMA and three in one SLMA patient) with successful PPV in all. Median insertion time (15 s) and glottic seal pressure (28 cm H(2)O) were similar in both groups. Median volume of air for cuff inflation to 60 cm H(2)O was 22.4 ml (PLMA) and 21.9 ml (SLMA). Median age and BMI: 50 yr (range 25-74), 51 yr (23-72) and 29 kg m(-2) (range 21-46), 30 kg m(-2) (20-42) in PLMA and SLMA groups, respectively. Mallampati score mean arterial pressures after induction, and 1 min after induction and insertion of the first device were similar. A lubricated gastric tube (16Fr) was passed at the first attempt in both devices: median gastric content 15 ml (5-75), 17.5 (5-124) and a median pH of 3 (1-6), 1.5 (1-6) in the PLMA and SLMA groups, respectively. Fibreoptic laryngoscopic scores of 1-2 were recorded in 29/36 in both groups. Insertion success, glottic seal pressure and gastric access were similar in SLMA and PLMA.