Buffalo chest refers to the pleuro-pleural communication that results in a single pleural cavity. Iatrogenic buffalo chest can occur following heart or heart-lung transplantation and other major thoracic surgeries. We present the case of malignant pleural mesothelioma in which iatrogenic buffalo chest after extended thymectomy caused bilateral pneumothoraces and contralateral dissemination of the disease. The free communication between bilateral pleural cavities had facilitated the rapid progression of tumor and the consequent bilateral malignant pleural effusions had made the management of disease much more difficult, leading to the early fatal outcome. To our knowledge, this is the first case of buffalo chest that was associated with bilateral malignant pleural effusions.