Pericardiocentesis is indicated for cardiac tamponade or in symptomatic pericardial effusions, two clinical situations often found in the intensive care unit (ICU). Bedside ultrasound is highly sensitive in identifying pericardial effusions with as little as 15 mL of fluid. Although tamponade is a clinical diagnosis, a bedside echocardiogram is also crucial in identifying key features that may suggest clinical tamponade, such as inferior vena cava plethora, right heart collapse in diastole, bulging of the interventricular septum during spontaneous inspiration, or mechanical expiration, and respirophasic changes in mitral and tricuspid inflow velocity on Doppler ultrasound. Once tamponade has been diagnosed, an ultrasound is necessary to improve the safety of bedside pericardiocentesis. Multiple approaches exist, including parasternal, apical, and subxiphoid. Ultrasound can be used to verify needle placement prior to catheterization of the pericardial space and can also be used to identify post-procedural complications.