A 3-day-old male baby with neonatal necrotising enterocolitis had a central line (Cavafex No. 18) inserted through the left femoral vein for administration of parenteral nutrition. Forty-eight hours later, he developed progressive abdominal distention with evidence of free abdominal fluid. A contrast injection done through the left femoral vein revealed retroperitoneal leakage of contrast from a traumatic rupture of the left iliac vein. The intravenous catheter was removed and he was treated conservatively with eventual recovery.