The high rate of complications, especially respiratory tract infection (RTI), reported in patients with chronic tracheostomy (CT) has discouraged physicians from using this method. However, previous studies of CT have concerned mainly hospitalized patients. We have followed the bacterial colonization patterns of the upper and lower respiratory tract and recorded all RTIs in 39 outpatients with CT during a 12-mo period. Patients were colonized with one or more potential pathogens at the stomal site and in the trachea in 95% and 83%, respectively, of all sampling occasions. Staphylococcus aureus, gram-negative enteric bacteria (GNEB), and Pseudomonas aeruginosa were the most common colonizing bacteria at these sites. Seventy percent of bronchial-protected brush cultures were negative, despite simultaneous heavy colonization of the stomal site or the trachea. Only 18 of 39 (46%) patients were treated with antibiotics because of RTIs on a total of 30 occasions during the study year. Of these, only five episodes of pneumonia in four patients were registered, corresponding to an incidence of about 10 per 100 person years. We conclude that outpatients with chronic tracheostomy can be managed with a low risk for developing severe RTIs, despite massive airway colonization with potentially pathogenic bacteria.