BACKGROUND: Previous studies reported the lack of interaction between propofol and neuromuscular blockers. The current study was designed to compare the influence of propofol to that of enflurane on the vecuronium. METHODS: Forty , either sex, adult patients, scheduled for elective surgery, were randomly assigned to two groups. Patients received either propofol (Group I n=20) or thiopental (Group II n=20) as an induction agent and anesthesia were maintained with either propofol-N2O-O2(Group I) or enflurane- N2O-O2(Group II). Before induction, initial twitch was obtained as a control with supramaximal stimulus. Neuromuscular contraction was monitored continuously and recorded on a relaxograph. Onset time (T0), clinical duration (T25), and recovery index (RI) were measured. RESULTS: Onset time and clinical duration of vecuronium were not significantly different between two groups. Mean recovery index was 18.5 min and 38.6 min in group Iand II, respectively. CONCLUSION: These results indicated that propofol, different from enflurane, did not have influence on the recovery index of vecuronium.