Objective:Ensuring airway patency and proper management of ventilation by anticipating difficulties that can occur in airway control are vital in prevent­ing anaesthesia-related complications. We aimed to determine the role of preoperative assessment findings in difficult airway management.Methods:In this study, critical incident records of difficult airway patients between 2010 and 2020 in the operat­ing room of Bursa Uludag˘ University Medical Faculty were retrospectively analysed. A total of 613 patients, whose records were fully accessible, were grouped as paediatric (under 18 years old) and adult (18 years and over).Results:The success rate for maintaining an airway in all patients was 98.7%. Pathological situations which cause difficult airways were head and neck region malignancies in adult patients and congenital syndromes in pae­diatric patients. Anatomical reasons that cause difficult airway were anterior larynx (31.1%) and short muscular neck (29.7%) in adult patients and small chin (38.0%) in paediatric patients. A significant statistical relationship was found between difficult mask ventilation and increased body mass index, male gender, modified Mallampati class 3-4, and thyromental distance <6 cm (P= .001,P< .001,P< .001, andP< .001, respec­tively). The correlation of Cormack–Lehane grading with modified Mallampati classification, upper lip bite test, and mouth opening distance was statistically significant (P< .001,P< .001, andP< .001, respectively).Conclusion:In male patients with increased body mass index, modified Mallampati test class of 3-4 and thyromental distance of <6 cm should suggest the possibility of difficult mask ventilation. In modified Mallampati classification and upper lip bite tests, the possibility of difficult laryngoscopy should be considered as class increases and mouth opening distance becomes shorter. Preoperative assessment, including a good history taken from the patient and a complete physical examination, is crucial to provide solutions for difficult airway management.