Different administration techniques of the muscle relaxant vecuronium were studied on the anterior tibialis muscle preparation of thiopentone, a chloralose anaesthetized dogs. The intubating dose, double intubating dose and the intubating dose after priming were studied. The time of injecting the top-up dose was chosen from our results to be at the maximal twitch depression of the priming dose. Our study demonstrated that, administration of the intubating dose (0.1 mg kg-l) of vecuronium 5 minutes after priming doses (0.01 and 0.02 mg kg-l) significantly reduced the onset time without altering the duration of action and recovery index. Likewise, the double intubating dose significantly decrease the onset time with a significant prolongation of the duration of action and recovery index. It could be concluded that, the priming appears to decrease the onset time rather than the duration of action and allowing rapid spontaneaus recovery. This is particularly important for the safety of patient's during intubation and in the immediate post-operative phase.