A device (1) for fixing tubes for the oral intubation of patients, comprising a flexible body (2) adapted to be arranged proximate to the mouth of a patient and a seat (3) associated with the body (2) for accommodating a respiration tube (T), provided with reversible means (4) for retaining the tube; the seat (3) comprises a longitudinal opening (5) for the insertion of the tube (T) inside it after insertion in the body of the patient by means of a movement of the tube transversely to its longitudinal extension.