OBJECTIVES: Training in mitral valve (MV) surgery is difficult because of its complex 3-dimentional anatomy and sophisticated surgical techniques. The goal of this study was to create an effective and simple simulator to enable the trainee in performing MV repair and replacement techniques in a low-fidelity environment. METHODS: The MV surgery simulator is a self-shaped sponge integrated into a portable box that can be used for an unrestricted number of procedures. The building process is detailed in this study. MV procedures were performed in which the surgical handling was tested. The total cost was calculated in euros. RESULTS: The building of the MV simulator resulted in the development of a new low-cost tool for training in MV surgery. The usage of the sponge led to building the MV components with flexible properties and allowing the surgical procedures to be performed in unrestricted numbers. This involved MV replacement in both intra- and supra-annular fashion and MV repair according to the Carpentier classification. CONCLUSION: Surgical skills in mitral surgery could be improved by usage of the low-fidelity simulator. The high cost of the training for residents and junior surgeons could be effectively reduced by using this low-cost, portable, reusable simulator and its accessories (ring and band). (C) 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.