—This paper presents a parallel algorithm for computer simulation of Electrocardiogram (ECG) based on a 3-dimensional (3D) whole-heart model. The computer heart model includes approximately 50,000 discrete elements (model cells) inside a torso model represented by 344 nodal points with 684 triangle meshes. The Poison question is applied to the volume conductor problem for simulation of ECG, which involves a maximum of about 50,000 electric current dipole sources and four boundaries including the torso surface and three surfaces of heart. A parallel algorithm was introduced to solve this problem based on Message Passing Interface (MPI). An implementation is conducted with a cluster computer system consisting of up to eight PCs, each of which has a dualcore processor. It was shown that the speedup is close to 2 in one PC and close to 8 with 8 processors, as compared to the serial algorithm. This study demonstrates a useful way of parallel computing in biomedical simulation study.