The most common tumors causing pleural metastasis in women are gynecological cancers, with breast cancer at the top of the list. However, the revelation of the latter by pleural effusion is rare. We report the case of a 61-year-old woman, with a history of well-controlled asthma since the age of 20, who was initially consulted for dyspnea stage III of the Modified Medical Research Council score (mMRC). Chest X-ray showed moderate bilateral pleural effusion. The pleural biopsy concluded with a pleural metastasis of breast carcinoma.