BACKGROUND Tracheal tube tip and cuff positions of different cuffed paediatric tracheal tube brands in the trachea can vary with design. METHODS Data from three clinical studies with measured tracheal lengths were pooled in a database including 422 children aged from birth to 16 yr. Dimensional data of seven cuffed paediatric tracheal tube brands (ID 3.0-7.0 mm) were recorded. Positions of tracheal tube tip and upper cuff border were calculated for each of the 422 tracheas using depth mark based tracheal tube placement, placement of the tracheal tube tip at a calculated safety distance above the carina, and mid-tracheal tube placement. Percentage of accidental bronchial intubations and tracheal tube cuff positions in the subglottic or supraglottic region were calculated. RESULTS Depth mark based tracheal tube placement resulted in accidental bronchial intubation of up to 18% of cases and tracheal tube cuffs being placed in the subglottic region in up to 91%. Tracheal tube tip placement at a calculated safety distance resulted in up to 54% of tube cuffs placed too high. Mid-tracheal tube placement led to 100% subglottic or supraglottic tracheal tube cuff positions. CONCLUSIONS All studied cuffed paediatric tracheal tubes have major design flaws potentially leading to airway complications. Tracheal tube manufacturers are urgently asked to improve the design of cuffed paediatric tracheal tubes. Alternative strategies for tracheal tube placement can allow safe tracheal tube placement of uncuffed but not of cuffed tracheal tubes.