In most cases, extubation may be safely performed in the operating rooms. However, some cases need leaving the endotracheal tube in place until the patient's condition is appropriate, usually in the Postaneshesia Care Unit (PACU) or Intensive Care Unit (ICU). We retrospectively reviewed the recovery room record of 4,241 patients who performed on operation under general anesthesia at Inha Hospital from January 1993 to December 1993, and then examined into details how many factors are influenced to the time of extubation following surgery. The results were as follows; 1) The overaU frequency of delayed extubation (or PACU extubation) was 9.8% (423/4,241). 2) The surgical disciplines which had the highest number and incidence of delayed extubations were the general surgery (172 cases) and dental surgery (25%), respectively. 3) According to sex, the male patients (243) outnumbered the female counterparts (180). 4) According to age, delayed extubation was most common among infants (<1 year of age) (21.4%). 5) According to operation site, delayed extubation occurred most commonly among operations involving upper abdominal regian (36.1%) followed by thoracic region (22.9%). In conclusion, extubation should be performed when the patient is nearly fuUy awake, of acceptable respiratory rate and depth, and when the effects of muscle relaxants have been fully reversed.