The device for locating cardiac arrhythmias comprises a three-dimensional reconstruction of the patient's torso and a number of surface electrodes, wherein the three-dimensional reconstruction of the patient's torso is generated through a number of images obtained by means of at least one camera. In particular, the device comprises elements for locating the surface electrodes, which detect the position of the electrodes with respect to the patient's torso, and data processing elements that generate, on the basis of the three-dimensional reconstruction and the position of the electrodes, a surface electrocardiographic map, and said surface electrocardiographic map has a number of data corresponding to readings of the surface electrodes related to areas of the three-dimensional reconstruction.