Introduction : It is known that stents for pediatric patients with congenital heart disease(CHD) must be capable of being redilated. There have been only a few studies concerning redilation procedures in this group of patients and nothing is known for stents other than Palmaz stent. The aim of this study was to evaluate the results and technical problems in redilation procedures of Palmaz stent(PS) and Jostent (JS) in patients with CHD. Methods : From August 1996 to April 2005, 45(52.3%) stents out of 86 implanted large-sized stents( 21 PS and 24 JS ) were redilated 31.8짹27.2 (4-87) months after implantation. The results and technical difficulties of the redilation procedure were investigated retrospectively. Results : Stenosis diameters increased (8.2짹2.8 to 11.8짹3.3 mm, p<0.01), and perfusions to the affected lung improved significantly (28.9짹12.8 to 36.1짹13.0%, p<0.01), after redilation. Fixed indentation was observed after initial redilation at moderate pressure in 9(20%) patients, which were disappeared or improved after redilation at high pressure in 4(44%) patients. Technical difficulties were encounterd in 3(6.7%) patients who had protruded proximal edge of stent in main pulmonary artery with 1 procedural failure due to inability of balloon catheter to pass through the stent. No fracture, compression, or significant restenosis of implanted stents was observed before and after redilation for both PS and JS, except one thrombotic occlusion of stent implanted on a unifocalized lobar pulmonary artery. There was no significant complication except a case of balloon rupture during rapid redilation. Conclusions : Redilation of stents is feasible, safe, and effective for both large Palmaz stent and Jostent. These stents offers appropriate radical force after redilation up to maximal diameter. Redilation procedure may be interfered by protrusion of stent beyond bifurcation. Fixed stenosis can be occasionally treated with double balloon technique at higher pressure.