BACKGROUND An incorrect position of umbilical venous catheters (UVC) is common and associated with a higher complication rate. METHODS From 2 545 neonates admitted between 1/1999 and 6/2008, 142 with UVC were extracted. The following factors that may influence the frequency of correct placement, bacterial growth on the catheter tip and infection were analysed: gestational age (GA), birth weight (BW), indication, sex, insertion site, insertion period (1999 to 2003 vs. 2004 to 2008) and indwelling time. RESULTS A central position was reached in 73,2%. The first insertion attempt was successful in 48,6%. The rate of successful insertion was higher in our own department compared to catheter insertions performed elsewhere. 4 life-threatening complications were observed (pericardial and pleural effusion, rupture of the catheter into the liver parenchyma, rupture of the catheter into the abdominal cavity). The risk of bacterial colonisation was associated with lower GA and BW. CONCLUSIONS The rate of central positioning with UVC is about 75%. Positioning was not influenced by GA, BW, indication, sex or insertion period. Severe complications can occur also in catheters with previous correct position. Because of the higher risk of colonisation and infection with longer indwelling times, the UVC should be removed as soon as possible.