To assess the safety and efficacy of percutaneous infraclavicular subclavian venipuncture in shocked patients, 172 consecutive cases were prospectively studied. Catheterization was successful in 163 patients (94.7%); in 119 (69.2%) of these only 1 attempt was required. Failure was encountered in 9 cases (5.2%). There were 9 (5.2%) serious complications, 4 requiring active treatment. Procedure-related mortality was nil. Extrathoracic placement of the catheter tip was detected on routine check chest X-ray in 24 cases (14.8%). Staff relatively inexperienced in the technique contributed 8 of the 9 complications and 6 of the 9 failures. Apparently, percutaneous infraclavicular subclavian catheterization in shocked patients is a relatively safe technique providing rapid access to a central vein.