Details of the preoperative condition, in particular symptoms of respiratory tract infections (RTI), perioperative management and the occurrence of perioperative complications, were collected in a survey of 2051 children. Logistic regression was used to determine which variables were predictors of anaesthetic adverse events. 22.3% of the children had symptoms of an RTI on the day of surgery, and 45.8% had a 'cold' in the preceding 6 weeks. Logistic regression returned eight variables. They were method of airway management, parent states the child has a 'cold' on the day of surgery, child has nasal congestion, child snores, child is a passive smoker, induction agent chosen, child produces sputum, and whether reversal agent used. Orotracheal intubation was associated with an increased probability of complications when compared with laryngeal mask airway and facemask. RTI in the preceding 6 weeks did not increase probability of complications. Wheeze, fever, malaise and age could not be excluded as predictors in this study because children with these symptoms and infants with colds were effectively excluded from the study.