Background Airway alterations found after endotracheal intubation are usually associated with mechanical trauma from the tube. However, no studies are available concerning alterations in airways that have never been intubated before. It was the aim of the study to compare endoscopic findings in the larynx and trachea of children who had undergone prior endotracheal intubation with findings in children who had not been intubated before. Methods In 1021 children aged from 0 to 6 years, rigid endoscopies were performed before planned elective endotracheal intubation. The anonymized endoscopy videos were reviewed and graded by five international airway experts. Data was compared between the two groups using the chi-square test (P = 0.05). Results Endoscopic records of 971 children (473 with prior intubation; 498 without prior airway intubation) were included in the final calculations. Most patients (93.7%) with prior intubation had been intubated with a cuffed tube. The number of intubations ranged from 1 to 27. The median interval between intubation and endoscopy was 0.53 years (0.0035.57 years). Abnormal findings were observed in 31.7% and 26.8% of patients with and without prior intubation, respectively (P = 0.063). Glottic granulomas were significantly more common after intubation (3.6% vs 1.4%; P = 0.028). The incidence of other abnormal findings was similar in both groups. Conclusion Endoscopic airway alterations can be observed in about one-quarter of children presenting for routine surgery without prior intubation. Except for glottic granulomas, the abnormalities are found with similar frequency in patients with and without prior intubation. No relevant airway damage from short-term endotracheal intubation was found.