Physicians spend a considerable amount of time and effort inserting catheters and needles into patients. Central venous catheters are the mainstay of measuring hemodynamic variables that cannot be assessed by noninvasive procedures. These catheters also allow hemodialysis, parenteral nutritional support, delivery of medications, and catecholamine administration. Arterial pressure catheters are frequently used for hemodynamic monitoring and for obtaining arterial blood gases in critically ill patients. Such use of arterial and central venous catheters, however, is potentially associated with severe complications that can be injurious to patients and expensive to treat. Techniques involving the use of anatomic landmarks have been the traditional mainstay of accessing the central venous system for decades. With the development and refinement of portable and affordable high-resolution ultrasound devices, imaging vascular access has changed the role of the traditional landmark techniques. In this article, we explain the use of ultrasound for vascular access to reduce complications associated with cannulation of veins and arteries. We will also provide a brief overview of the current literature regarding ultrasound-guided vascular access.