In neonates with duct-dependent congenital heart defects, a reliable non-pharmacological, non-surgical method of maintaining flow through the arterial duct may simplify the management. Stent implantation into the arterial duct has been proposed as such a method. In order to evaluate the technical difficulties which may accompany clinical application, stent implantation into the arterial duct was attempted in 32 newborn lambs aged two to nine days (mean 4.2±1.4) weighing 2.4–7.3 kg (mean 4.6±1.0). Four different types of stent were implanted and the ease of implantation and outcomes were assessed. Stent implantation was technically successful in 28 of the 32 lambs (88%). Of these, 11 lambs died shortly after stent implantation with patent ducts, five lambs had early occlusion of the duct and 12 lambs were entered into a long-term study. The Gianturco-Roubin stent was too rigid and too long to enable successful implantation. The Palmaz-Schatz stent was poorly radio-opaque and was difficult to place accurately. When the aortic orifice was not completely covered, the duct occluded within a few days of implantation. The articulation gap also allowed duct tissue to prolapse into the middle of the stent. The Medinvent and Tower stents were simpler to position due to their superior radio-opacity. The Tower stent had an additional advantage in being a single strand stent which could be easily retrieved if misplaced.