Thoracentesis, or pleural puncture, is a percutaneous procedure in which a needle, catheter, or cannula is inserted into the pleural space when it is pathologically and abnormally occupied by air or fluids such as exudate, transudate, or blood. Typically, this procedure can be used for diagnostic or therapeutic purposes [1,2]. This method is primarily indicated when the goal is to clarify the etiology of a small-volume pleural effusion (<30 mL), provided that it is sufficient to create a “safe window” with a fluid depth of at least 10 mm as visualized by ultrasonography. The removal of only 50 mL of fluid is sufficient for laboratory analysis and determination of possible causes.An exception to choosing this option is the presence of a small amount of fluid associated with a clear clinical diagnosis, such as pneumonia, or when the patient has congestive heart failure with classic findings, such as bilateral pleural effusions and pulmonary edema [2].The primary intent of this indication is symptomatic or preventive relief [2]. In this context, the procedure is performed in cases of large or symptomatic pleural effusions; tension pneumothorax, prior to chest tube drainage; and hemothorax, as it allows symptom relief—such as dyspnea—and helps prevent the risk of pleural thickening and restrictive functional impairment [1].In general, thoracentesis should be considered on an individual basis for each patient. Not only is the clinical condition important, but also the balance between risks and benefits. Nevertheless, some contraindications to this procedure can be cited, namely: insufficient amount of pleural fluid; skin infection or wound at the needle insertion site; and severe hemorrhagic diathesis, given the need to weigh the likelihood of bleeding into the pleural space as well as the patient’s ability to tolerate a hemothorax and a procedure to drain intrapleural blood, if necessary [1].