Benign pleural effusions are twice as common as malignant effusions and have diverse causes and manifestations, which often makes them a diagnostic challenge. Differentiating effusions as a transudate or exudate is the first, and often helpful, step in directing investigations for diagnosis and management. Congestive heart failure and hepatic hydrothorax are the commonest causes for a transudative effusion. Commonly exudative effusions are caused by infections or may be secondary to pulmonary embolism, drugs, collagen vascular diseases, or may follow cardiac surgery. This article gives an overview of the causes and management of common benign pleural effusions. © 2013 Elsevier Inc.