Left atrial thrombus is frequently associated with rheumatic mitral valvular heart disease. Left atrial thrombus is usually attached to the atrial wall, but rarely it is freely floating in the cavity. In that case the patient may present with the symptoms of acute hemodynamic decompensation due to the so-called "hole-in-one" effect or multiple systemic embolism. We report a case of multiple systemic embolism associated with left atrial free-floating ball thrombus in mitral valvular heart disease.