A 60 year-old female complained with abdominal distension for one month. Stage IIIc, grade 2 clear cell carcinoma of the ovary was diagnosed after laparotomy. Weekly paclitaxel combined with carboplatin as adjuvant chemotherapy was given after optimal cytoreductive surgery. An acute cerebral infarction after first chemotherapy cycle was developed. The patient presented with dyspnoea after the third chemotherapy cycle and the symptom could be relieved at rest. Such symptom worsened and relieved alternatively for 3 days. A sudden dyspnoea occurred to the patient again when she got up one night, and died of respiratory and circulatory failure on the way to the hospital. Autopsy revealed ovarian clear cell carcinoma with metastasis to the whole pelvic and abdominal cavity and massive pulmonary arterial embolism (the length of embolus is 20 cm) with cerebral infarction. A conclusive remarks was made during the conference that patients who underwent operation and chemotherapy were at high risk for venous thrombosis (VT) and pulmonary embolism (PE). It was important to analyze a patient's individual risk for VT and PE. Appropriate thrombosis prophylaxis ought to be considered highly for high risk patients.