We evaluated ultrasonic examination as a diagnostic tool for catheter misplacement and pneumothorax after central venous catheter insertion. Physicians in the intensive care unit (ICU) performed the ultrasonic examinations, and the results were compared with those of chest radiography. Eighty-five central venous catheters (70 subclavian and 15 internal jugular) were inserted into 81 patients; 10 misplacements and one pneumothorax occurred. Ultrasonic examination feasibility was 99.6%. The only pneumothorax and all misplacements except one were diagnosed by ultrasound. Taking into consideration misplacements and pneumothorax research, ultrasonic examination did not give any false positive results. The mean time of the entire ultrasonic examination was 6.8 +/- 3.5 min, whereas 80.3 +/- 66.7 min were needed for the radiography (p < 0.0001). This study has suggested that ultrasonic diagnosis of catheter misplacement and pneumothorax related to central venous catheterization is a rapid and accurate method that can be easily performed by ICU physicians.