INTRODUCTION: Umbilical venous catheters (UVCs), commonly inserted in neonates for vascular access, are not without complications. METHODS: A single-centre retrospective cohort study that reviewed complications related to UVC insertion in neonates was conducted in a tertiary neonatal unit in Singapore from January 2016 to July 2017. Ideal UVC position was defined as catheter tip within 0.5 cm above or below the diaphragm. Catheter-related sepsis was defined as clinical or biochemical abnormalities suggesting any new-onset or worsening sepsis 72 hours before or after removal of UVCs, with or without positive culture. Catheter-associated bloodstream infection (CABSI) was defined as positive microbiological growth in one or more blood cultures obtained from a symptomatic infant up to two days after UVC placement or within 48 hours of catheter removal. RESULTS: 108 patients had UVC insertions. Mean gestational age and birth weight were 30.4 ± 4.0 weeks and 1,536.2 g ± 788.9 g, respectively. Mean UVC duration was 6.6 days. The UVC was in an ideal position in 27 (25.0%), deep in 13 (12.0%) and short in 35 (32.4%) neonates. One-third of the UVCs (n = 33) were malpositioned. Catheter-related sepsis was observed in 16 (14.8%) neonates, with 5 (4.6%) having CABSI. The most common organism was coagulase-negative Staphylococcus. Other complications include peritoneal extravasation in 3 (2.8%) patients, with two requiring surgical intervention. Venous thrombosis occurred in 2 (1.9%) neonates and was managed conservatively. CONCLUSION Although complication rates were in line with international norms, UVCs were associated with serious complications and should be judiciously used.