A 45 year-old woman underwent a laparotomy for a giant ovarian tumor under general anesthesia. Preoperative CT scan revealed a 30 cm-diameter tumor compressing IVC. She had slight respiratory discomfort on supine position, but respiratory function test showed no abnormalities. In the operating room, after oxygenation for 3 minutes, general anesthesia was induced with fentanyl 100 μg, propofol 90 mg and rocuronium 40 mg on supine position. Immediately after the induction, her systolic blood pressure and heart rate fell to 45 mmHg and 40 beats per minute, respectively. We considered that her hemodynamic instability was supine hypotensive syndrome due to giant ovarian tumor. Therefore we placed her 30 degree right side up and pushed her tumor to the left so as not to compress the IVC. We rapidly injected acetated Ringer's solution 500 ml, ephedrine 12 mg and phenylephrine 0.1 mg, and her hemodynamic status soon recovered to normal ranges. The anesthetic induction of a patient with a giant ovarian tumor is challenging. Some reports recommend strategies such as induction on lateral position or suctioning tumor contents before induction. Careful induction of general anesthesia is required for these patients.