Cisatracurium and vecuronium both conferred the same hemodynamic stability but there was evidence of histamine release with cisatracurium. We conclude that vecuronium has a clinical onset faster than cisatracurium, better intubating conditions, more sensitivity to the neostigmine and hemodynamic stability with no evidence of histamine release. So, vecuronium may be more suitable than cisatracurium for use in outpatient anesthesia.