The aim of this study was the medico-economic evaluation of the closure of ostium secundum type interatrial communications in 32 patients, treated by cardiac catheterisation (group A: n = 17) or by surgery (group B: n = 15). The success rate was 100% with the 2 techniques. With national cost scale data we evaluated the overall cost of the 2 treatments using the information system medical program, starting from homogenous groups of patients: 150 catheterisation, 169 and 170 surgery. As the value for the homogenous group of 150 patients was much lower than the price of the material used for catheterisation, an adjusted group of 150 patients including the price of this material was created. An evaluation in terms of an artificial index of activity was also performed. The average duration of hospital stay for group A was reduced by 6.1 days compared to group B (p < 0.001). The overall cost was lower in group A than in group B (p < 0.001), using the real and "adjusted" homogenous group of 150 patients, with a respective reduction of 7,582 Euros and 3,731 Euros. Surgery and catheterisation scored 8,167 points (17,756 Euros) and 2,726 points (5,926 Euros) per patient respectively on the artificial activity index. In conclusion, catheterisation reduced the duration of hospital stay and brought an economic benefit for the Assurance Maladie compared to surgery. However, surgery is more profitable for the hospital than catheterisation because of the high cost of the prosthesis, which is not taken into account with a homogenous group of non-specific patients. This could hamper the development of this innovative technique in a hospital subjected to overall budgetary constraints.