Pleural effusion is a common presentation for many pulmonary and systemic diseases, particularly heart failure, pneumonia, cancer and tuberculosis (TB).Clinical care of pleural diseases is fragmented among medical specialists, including pulmonologists, thoracic surgeons, internists, intensivists, oncologists, cardiologists and infectious disease physicians. Standardization of practice is therefore difficult, and treatment of pleural effusions can vary significantly. The variations in clinical care of pleural diseases are in part due to the lack of high quality research to guide practice. It is therefore heartening to see a growing amount of research in pleural diseases, including large randomized trials, to address crucial questions. In any scientific exploration journey, the discovery of knowledge raises questions and promotes healthy debates on new controversies. In this special issue of the Journal of Thoracic Diseases, leading pleural specialists have provided reviews on the latest advances and controversies in pleural medicine.