We aimed to study the feasibility of a comfortable and secure intubation achieved with the Disposcope endoscope or Macintosh laryngoscope when glottis viewing is difficult. Forty adults scheduled for elective surgery under general anesthesia, in whom glottis viewing was difficult with the Macintosh laryngoscope (classified as Cormack-Lehane Grade III or IV), were randomized into 2 groups (N = 20 each): Disposcope endoscope (Group D) and Macintosh laryngoscope (Group M). We recorded the successful glottis viewing rate; intubation time; successful intubation rate; incidence of systolic blood pressure (SBP) >= 140 mmHg and heart rate (HR) >= 90 bpm from the beginning of intubation to 5 min after intubation; and postoperative sore throat and hoarseness. Successful glottis viewing rate and successful first intubation rate were higher in Group D than in Group M (P < 0.05);the number of intubations taking > 3 min and with SBP >= 140 mmHg and HR >= 90 bpm were less in Group D (P < 0.05). The visual analogue scale of postoperative sore throat 1 day after extubation was higher in Group M than in Group D ( P < 0.05). No significant differences were found in other indices ( P > 0.05). Better stability of hemodynamics, less intubation time, higher successful first intubation rate, and fewer incidences of postoperative sore throat were achieved in Group D than in Group M. Thus, comfortable and secure intubation can be achieved using the Disposcope endoscope in patients in whom glottis viewing is difficult.