The quality of laryngoscopy and tracheal intubation with propofol augmented by alfentanil was investigated as an alternative technique for rapid tracheal intubation. 119 patients aged between 18 and 60 years (ASA 1 and 2) undergoing elective surgery were prospectively studied in a randomized double-blind controlled fashion. Tracheal intubation facilitated by suxamethonium 1.0 mg/kg alfentanil 15 mu g/kg alfentanil 30 mu g/kg or saline control was compared after propofol induction. The quality of laryngoscopy and intubation were graded according to jaw relaxation, ease of insertion of the endotracheal tube and coughing on intubation. Failure to intubate occurred in 4% and 17% with alfentanil 15 mu g/kg and saline control respectively Tracheal intubation was successful in all patients with alfentanil 30 mu g/kg and suxamethonium 1.0 mg/kg. Alfentanil 15 mu g/kg was not statistically significantly different from saline (P = 0.112). Alfentanil 30 mu g/kg provided similar overall intubating conditions (P = 0.5) to suxamethonium 1.0 mg/kg. Alfentanil in both dosages effectively attenuated the haemodynamic responses to laryngoscopy and tracheal intubation.