<h3>Introduction</h3> Large mediastinal tumors are rare and have a wide spectrum of presentations. Herein we present a case of right ventricular failure in the setting of a large anterior mediastinal chondrosarcoma. <h3>Case presentation</h3> 32 year old male with no known significant past medical history presented with one week of severe cough and chest pain. CT scan showed a large anterior mediastinal mass (9.3 × 12.4 × 13.6 cms), and biopsy was consistent with chondrosarcoma. Three weeks later, patient underwent complete surgical resection of mass along with partial chest wall, pericardium and diaphragm resection and reconstruction. Postoperative echocardiogram (TTE) showed severe right ventricular (RV) dysfunction and severe tricuspid regurgitation. Pulmonary Hypertension and Right heart failure service was consulted for further evaluation. <h3>Decision making</h3> Review of postoperative TTE showed no signs of pulmonary hypertension (systolic notching, septal flattening, RV hypertrophy). Review of preop TTE showed distal 2/3 of RV obscured by mediastinal mass and basal 1/3 RV hypokinetic. Review of chest CT from one month prior to surgery revealed large anterior mediastinal mass severely compressing distal third of RV along with significant right atrial enlargement. Two possible hypotheses for RV failure were contemplated at this point. 1. Chronic compression of right ventricle leading to severe geometric distortion/increased wall tension of non-compressed RV segments leading to myocardial dysfunction. 2. Acute surgical injury or chronic compression of right coronary artery leading to infarct and scar. Patient was diuresed and TTE done on postoperative day 5 showed significant improvement in RV size/function. Repeat TTE done on postoperative day 30 showed further improvement in RV size/function. These findings suggest direct myocardial compression as a more likely etiology of RV failure as opposed to infarct. <h3>Conclusion</h3> This case presents a rare case of large mediastinal mass causing right ventricular dysfunction by compression. This case also illustrates the importance of multimodality imaging (TTE and CT) in the evaluation of RV failure.