The complications of central venous catheters used for immediate postoperative nutrition and monitoring were evaluated in 120 patients. Two patients had to be excluded due to an irregular protocol. 149 central venous catheters were placed in the remaining 118 patients. As to the access, the subclavian vein was used in 72.3%, the v. jugularis interna in 18.9%. The catheters were in average 11.7 days in place giving a total of 1392 catheter days. The end of therapy was the most frequent reason for removal of the catheter (81.6%) followed by septic (4.1%) and mechanical problems (8.8%). Venous thrombosis was observed in 2 patients, and embolisation of a catheter fragment and acute infusothorax each in 1 patient. 13% of the catheters were found to be malpositioned, and malposition was identified as a risk factor for thrombosis.--It is concluded from the comparison of these results with the literature, that the central venous catheter for parenteral nutrition has a risk of complication greater than 5% and therefore requires a clear indication. X-ray-control of catheter position is obligatory and malpositioned catheters are to be corrected. If the parenteral regimen is low in glucose concentration and osmolarity, blood sampling and monitoring via the same central venous line does not appear to increase the rate of complications.