A 59-year-old woman was admitted with dyspnea. A chest X-ray film revealed a large amount of pleural effusion at the both sides. No malignant cells were found in bilateral pleural effusions. Computed tomography (CT) of the abdomen showed a huge mass of the right ovary with a small amount of ascites, suggesting a diagnosis of Meigs syndrome. The ovarian mass and the neighboring organs, including the uterus and the greater omentum, were surgically removed, and then both the bilateral pleural effusion and ascites disappeared after the surgery. The histopathological examination revealed that the mass was clear cell adenocarcinoma of the ovary (stage IIc), indicating that the disease was pseudo-Meigs Syndrome. This is the second report of pseudo-Meigs Syndrome caused by clear cell adenocarcinoma of the ovary in Japan.