A dilator (10) for creating tracheostomies in one pass. Dilator (10) includes a generally linear shaft (12) extending from a proximal end (14) and beginning at a distance therefrom, gradually and continuously through a curved distal portion (16) of continuously decreasing diameter (from about 38 french) to a distal tip portion (18) of small diameter of about 12 french at distal end (20). The outer surface of the insertable portion is treated or hydrophilically coated to minimize friction, and the gradual taper gradually widens the tracheal entrance opening (44) between tracheal rings (46,48) with minimal trauma. The wall thickness gradually decreases from the linear shaft (12) to the soft distal tip portion (18). The continuing curve of the distal portion (16) enables the increasingly longer inserted portion of the dilator to remain situated in the trachea (50) during insertion and for the distal tip portion to clear the posterior tracheal wall.