Severe mitral annular calcification represents a significant challenge for valve replacement, particularly in elderly patients with comorbidities, in whom conventional surgical approaches are associated with high morbidity and mortality. In such cases, percutaneous and minimally invasive transatrial approaches have emerged as therapeutic alternatives. The latter, unlike the former, allows direct visualization of the annulus, resection of the anterior leaflet, and more accurate prosthesis positioning, reducing malposition, embolization, paravalvular leak, and left ventricular outflow tract obstruction. We present the case of an 81-year-old woman with severe mitral stenosis and extensive annular calcification, who underwent transcatheter mitral valve replacement via open transatrial access. The surgical technique and postoperative course up to hospital discharge are described. This is the first reported case in Chile using this technique, providing evidence of its feasibility in patients with severe mitral annular calcification and high surgical risk.