We investigated the diagnostic accuracy of a documented previous difficult tracheal intubation as a stand-alone test for predicting a subsequent difficult intubation. Our assessment included patients from the Danish Anaesthesia Database who were scheduled for tracheal intubation by direct laryngoscopy. We used a four-point scale to grade the tracheal intubation. A previous difficult intubation was defined according to the presence of a record documenting a difficult penultimate tracheal intubation-score for the 15 499 patients anaesthetised more than once. Our assessment demonstrates that a documented history of previous difficult or failed intubation using direct laryngoscopy are strong predictors of a subsequent difficult or failed intubation and may identify 30% of these patients. Although previous investigators have reported predictive values that exceed our findings markedly, a documented previous difficult or failed tracheal intubation appears in everyday anaesthetic practice to be a strong predictor of a subsequent difficult tracheal intubation.