<i>Background/Aims:</i> So far, surgical and interventional therapies for muscular ventricular septal defects (mVSDs) beyond the moderator band have had their limitations. Thus, alternative therapeutic strategies should be developed. We present a new animal model for the evaluation of such strategies. <i>Methods:</i> In a pig model (n = 9), anterolateral thoracotomy was performed for exposure of the left ventricle. mVSDs were created under two- and three-dimensional echocardiography with a 7.5-mm sharp punch instrument, which was forwarded via a left ventricular puncture without extracorporeal circulation. <i>Results:</i> Creation of mVSDs was successful in all animals (n = 9) confirmed by echocardiography, hemodynamic measurements and autopsy. The defects were located in the midmuscular (n = 4), apical (n = 1), inlet (n = 2) and anterior part (n = 2) of the muscular septum. All animals were hemodynamically stable for further procedures. The diameter and shunt volume of the mVSDs were 4.8–7.3 mm (mean: 5.9 mm) and 12.9–41.3% (mean: 22.1%), respectively. Autopsy confirmed in all animals the creation of a substantial defect. <i>Conclusion:</i> The described new technique for creation of an mVSD on the beating heart in a pig model is suitable for the evaluation of new therapeutic strategies for mVSD closure.