Pleural effusion of carcinomatous pleurisy is relatively common and a significant problem in recurrent breast cancer patients. It's very important to control it to keep a good quality of life for those patients. Two recurrent breast cancer patients, suffering from carcinomatous pleurisy and dyspnea due to pleural effusion, were treated with distilled water. As they have been treated with many kinds of hormonal therapy or chemotherapy for their several distant metastases, the performance status of these therapies has not been good. After one or two distilled water pleurodesis, pleural effusion was well controlled and dyspnea had disappeared. No adverse events, such as high fever and chest pain concerning this distilled water therapy were experienced. Taking its efficacy and a rarity of adverse events, distilled water plerodesis is a useful treatment for pleural effusion of carcinomatous pleurisy.