To evaluate the frequency of respiratory adverse events during general anesthesia in children passively exposed to cigarette smoke (PSE).Prospective, double blinded, observational study.Operating room and recovery room of a university hospital.Data were collected from 385 children who underwent elective surgery during general anesthesia from June to November, 2008. PSE was identified by using the child's caregivers' information. Respiratory adverse events were recorded during anesthesia and post-anesthesia.Technique of anesthesia induction and management, distribution of patients' age, gender, surgical procedures, and perioperative analgesic methods were similar in the PSE and non-PSE groups. Respiratory adverse events were reported in 58 patients (15.1%): 50 patients (21.4%) were in the PSE and 8 patients (5.3%) were in the non-PSE group (P = 0.00). The frequency of laryngospasm during anesthesia (P = 0.03) and hypersecretions in the recovery room (P = 0.00) were significantly increased in the PSE group.Children who are exposed to environmental tobacco smoke and who undergo general anesthesia seem to have an increased risk of respiratory complications in the recovery period rather than during anesthesia.