Mycotic aneurysm, uncommon complication of infective endocarditis (IE), develope more often in patients with subacute IE than acute IE. We report an unusual case of acute endocarditis complicated with multiple mycotic aneurysm and mitral valve perforation. 42 year old man who are referred for management of uncontrolled fever and dyspnea was diagnosed as acute mitral valve infective endocarditis caused by Staphylococcus aureus. He got complication of mycotic aneurysm on right femoral artery and mitral valve perforation with severe mitral regurgitation during favorable course of antibiotic treatment. Mycotic aneurysm was successfully treated with endovascular coil insertion and thrombin injection and mitral valve replacement was performed. On second day after operation, he died due to catastrophic intracranial hemorrhage which suggests another mycotic aneurysm rupture.