Pleural effusion is one of the most commonly encountered clinical conditions. Pleural effusion is defined as accumulation of abnormal quantity of fluid in the pleural cavity; normally pleural cavity contains only 5−15 ml. Pleural fluid accumulates due to either excess production or inadequate drainage of the fluid. Cardinal features of pleural effusion include chest pain which increases by breathing, movement and sneezing, other is breathlessness and abnormal radiograph. Parapneumonic effusions, tuberculous effusion, fungal pleural effusion, primary pleural tumors, hemothorax are some of the common types that occur. Pleural effusions are common in cardiac diseases. Various examination are done, X-ray is the simplest, easy and economical investigation for the diagnosis of pleural effusion. Thoracoscopy is a procedure done to visualize the pleural pathology. CT scan, ultrasound are important, indispensable tool of investigation particularly in pleural effusions. There is a need for precise diagnosis to reduce the morbidity and mortality and for appropriate management.