INTRODUCTION: It is difficult to successfully suction the left bronchial tree. We evaluated the success rate of left bronchial cannulation with a new closed-suction directional-tip catheter (Trach Care directional-tip catheter, TCDT, Ballard Medical Products, Midvale UT). Success rates were compared in patients with endotracheal and tracheostomy tubes. We also studied the effects on success rate of (1) the distance of the endotracheal tube from the carina, (2) the tube's bevel orientation, and (3) the tube's position in the patient's mouth. METHOD: At the time of the routine daily chest radiograph, 75 attempts at left bronchial cannulation were made in 45 patients. With the head maintained in a midline position, the TCDT catheter was advanced with the radiopaque blue line in the 1 o'clock position. The radiograph was evaluated for correct placement of the TCDT catheter. RESULTS: Due to lung pathology and x-ray technique, catheter placement could not be interpreted in 17% of the radiographs. In the remainder, overall success rate was 71% (79% with tracheostomy tubes and 67% with endotracheal tubes, not significantly different, with p > 0.3). Tube distance from the carina and bevel orientation did not significantly affect success rates. Success rates for tubes located in the left and central positions of the patient's mouth were significantly better (p < 0.002 and p < 0.03, respectively) than for tubes located on the right side of the patient's mouth. With the endotracheal tube on the left side of the patient's mouth, the success rate was 89%. CONCLUSION: We conclude that the TCDT catheter successfully combines the features of a closed-suction system with those of a directional-tip catheter that allows selective bronchial cannulation, a large percentage of the time.