OBJECTIVE The study aim was to create a new form of mitral valve surgery with a novel stentless mitral valve (SMV) made from autologous pericardium, for use in patients with an unrepairable valve. METHODS A newly designed two-leaflet SMV ('NORMO') was developed, the excellent hydrodynamic function of which had been evaluated previously using a pulsatile simulator (data reported elsewhere). The operation involved constructing the NORMO valve by using autologous pericardium and a flexible ring, before instituting cardiopulmonary bypass and implanting the valve. The new-style operation was performed successfully in seven patients with complicated mitral valve disease who had requested valve repair rather than replacement. RESULTS Postoperative echo-Doppler studies of the seven patients, performed at between six and 26 months (mean 18 months) after surgery, revealed mild mitral regurgitation (MR) in two cases and no or only trivial MR in the other five cases. CONCLUSIONS Although its long-term durability is unknown, this new surgery might represent an alternative for mitral valve repair, especially in those patients with a complicated valve pathology where the feasibility of repair is low.