Background: We investigated whether the intubating condition change acoording to the methods of administration of propofol and rocuronium. Methods: Ninety adult patients (ASA physical status I or II) undergoing elective surgery were randomly assigned to one of three groups; Group I (n = 30) received rocuronium (0.6 mg/kg) after administration of propofol (2 mg/kg), Group II (n = 30) received propofol and rocuronium simultaneously via different intravenous routes, and Group III (n = 30) received a mixture of propofol and rocuronium via same intravenous route. Intubation was attempted at 60 seconds after administration of rocuronium. Hemodynamic parameters (mean blood pressure, heart rate) were measured before and after propofol administration with 20 seconds interval. Intubating conditions (jaw relaxation, vocal cord movement, and response to tracheal intubation) were evaluated as excellent, good, fair and poor. Train of four counts were recorded at 60 seconds after administr