BACKGROUND: Invasive central venous catheterization is necessary in critically ill patients for hemodynamic monitoring and for administration of hypertonic fluids, drugs, and parenteral nutrition. Common access sites are the internal jugular veins, subclavian veins, and femoral veins. Yoffa's percutaneous supraclavicular subclavian vein catheterization technique has some disadvantages and difficulties which include dislodgement of the puncture needle and difficult enhancement of the guide wire. To overcome these problems, we modified Yoffa's technique as a symmetrical puncture against the clavicle. METHODS: A patient was placed supine with his/her head turned to the opposite side with the arm at the side. The needle was inserted through the skin at a point around 1 cm below the clavicle, toward the imaginary midline of the clavicular head of the sternocleidomastoid muscle (SCM). The guide wire was inserted with a J-wire. Measurements were made to determine the length from the puncture site to the lower border of the clavicle, the depth and angles from the needle to mid sagittal line, the coronary line and skin (Fig. 2). We also evaluated the No. of punctures, wire insertions, and complications. RESULTS: Our success rate was 95.1% and 6 cases with complications (5.9%) occurred in 102 attempts. The most serious complication was a delayed tension pneumothorax 6 h postoperatively. CONCLUSIONS: These results suggest that the new landmark for infraclavicular subclavian vein catheterization is an easy and safe procedure for an experienced physician. We also recommend close observation postoperatively for at least 24 h for complications.