The "Timing Principle" utilises a single bolus of nondepolarising neuromuscular blocking drug followed by thiopentone given at the onset of clinical weakness. The purpose of this study was to compare the intubating conditions after succinylcholine and after atracurium used according to the "timing principle." Eighty patients were randomly assigned to four groups of 20. Three study groups were given atracurium 0. 5, H and III respectively)