Malignancy is one of the most common causes of exudative effusions and increases in incidence in the elderly. Lung cancer is the most common cause of malignant effusion caused by contiguous spread and its propensity to invade the pulmonary vasculature and embolize to the visceral pleura. Lung, breast, ovary, and gastric cancer and lymphomas account for about 80% of all malignant effusions. Dyspnea and cough are the most common symptoms at presentation. Thirty percent of patients have a low pleural fluid pH (> or = 7.30) and glucose (> 60 mg/dL) at presentation, which predicts a decreased survival, an increase yield on diagnostic studies, and a poor response to chemical pleurodesis. Talc by poudrage or slurry is the most successful pleurodesis agent. Pleural peritoneal shunt is an option for patients with an intractable, symptomatic malignant effusion who cannot undergo or who have failed pleurodesis.