Background: The pig has a similar anatomy and physiology to humans, and is thus one the most successful large animal models used in cardiovascular research. Piglets grow at a very fast rate during their first six months of life and therefore their use has the potential to provide a viable model to test the growth characteristics of a paediatric tissue-engineered vascular graft.Objective: To validate a juvenile piglet model for left pulmonary artery graftingMethods: Standardised anaesthetic and surgical protocols were used in accordance with Home Office requirements. Eleven five-week-old piglets (mean weight 10.5 kg) underwent general anaesthesia with use of neuromuscular blocker (Pancuronium 0.2 mg/kg/h, intravenous administration), insertion of central jugular line and arterial femoral line. Following a left posterolateral thoracotomy, the left pulmonary artery was dissected, systemic heparin was administered and two clamps were placed on the artery to enable the implantation of an experimental graft. A chest drain was inserted at closure. Piglets were continuously monitored during a 48-hour recovery period, with intermittent measurements of heart rate, blood pressure, respiratory rate, oxygen saturation and rectal temperature. Results: All piglets survived the surgical procedure. One out of eleven piglets died during the first two hours of recovery due to suspected anaesthetic withdrawal rebound. One piglet showed severe serosanguineous pleural effusion and hypoxia needing multiple chest drain suctions. Four piglets presented with a superficial wound infection in the first week after surgery, leading to an additional course of antibiotics. No further deaths or undesired events occurred up to six months following surgery. Conclusion: A piglet model for left pulmonary artery grafting has been validated. It is associated with low mortality and morbidity with a rapid postoperative recovery and no major complication. Obtaining a successful piglet model for pulmonary artery grafting will allow the evaluation of the growth of a paediatric tissue-engineered vascular graft.