Peripartum cardiomyopathy (PPCM) is a disorder of unknown cause in which heart failure occurs during the peripartum period. A 32-year-old woman was diagnosed with PPCM 10 days after delivery. One month after the initial diagnosis, a newly formed left ventricular (LV) apical thrombus was revealed and warfarin was started. One week later, the thrombus became mobile and she underwent surgical thrombectomy. Warfarin was restarted on postoperative day (POD) 1; however, thrombi recurred at POD 3. Intravenous heparin was then supplemented, which subsequently resolved the thrombi without any embolism. Although there is currently no consensus as to whether patients with depressed LV function and sinus rhythm should be anticoagulated to prevent thrombus formation, PPCM presents a higher risk and might need aggressive and pre-emptive anticoagulation once diagnosis is made.