The reconstruction of stenotic aortic valves has gained interest. In this study, the risk of decalcified human aortic valve tissue recalcifying was evaluated in vitro. Leaflets were removed and decalcified surgically. Calcium content in heavily calcified, macroscopically non-calcified and decalcified tissue was determined. 'Non-calcified' and decalcified tissue was incubated with calcium-containing medium to determine its potential for recalcification. All calcified specimens contained excessively high calcium levels. Calcific deposits could be effectively removed by surgical dissection, but the tissue rapidly re-accumulated calcium. Scanning electron microscopy revealed a loss of endothelial coverage in calcified areas, and decalcification led to an irregular surface. Even macroscopically normal tissue showed only partial endothelial coverage. Despite effective removal of calcium, valve decalcification leaves structures that re-accumulate calcium in vitro. Even normal-appearing tissue from diseased valves has a high potential for calcification. These findings support the observation of only limited clinical benefits after valve reconstruction for aortic stenosis.