Use of X-ray contrast allows us to differentiate between two or more adjacent structures on radiographic studies. The X-ray contrast agent can be the one with increase X-ray absorption, like iodine and a barium X-ray contrast agent or the one with decrease X-ray absorption like air and carbon dioxide contrast agent. Each contrast agent possesses different risks and benefits in various ways. Carbon dioxide as an intravascular contrast agent can be used as an alternative intravascular contrast agent and has superior results in some cases. In patients with renal dysfunction or iodinated contrast allergy, the use of Iodinated Contrast Agent poses the risk of considerable morbidity. Similarly, use of Gadolinium is discouraged in subject with severe renal dysfunction. Use of carbon dioxide(CO_2) as an intravascular contrast, offers an alternative in such patients for certain procedures, as it is not nephrotoxic and it does not incite allergic reactions. It is inexpensive, readily available and due to its unique physical properties, it can be used to image a wide variety of vascular beds and chambers. The aim of this paper is to systemically review the current literature to describe the indications, contraindications, adverse effects, instruments, precautions, latest methodologies and data supporting for the use of CO_2 as a contrast agent. Use of X-ray contrast allows us to differentiate between two or more adjacent structures on radiographic studies. The X-ray contrast agent can be the one with increase X-ray absorption, like iodine and a barium X-ray contrast agent or the one with reduced X-ray absorption like air and carbon dioxide contrast agent. Each contrast agent possesses different risks and benefits in various ways. Carbon dioxide as an intravascular contrast agent can be used as an alternative intravascular contrast agent and has superior results in some cases. In use with renal dysfunction or iodinated contrast allergy, the use of Iodinated Contrast Agent poses the risk of considerable morbidity. Use, Gadolinium is discouraged in subject with severe renal dysfunction. Use of carbon dioxide (CO_2) as an intravascular contrast, offers an alternative in such patients for certain procedures, as it is not nephrotoxic and it does not incite allergic reactions. It is inexpensive, readily available a nd due to its unique physical properties, it can be used to image a wide variety of vascular beds and chambers. The aim of this paper is to systemically review the current literature to describe the indications, contraindications, adverse effects, instruments, precautions, latest methodologies and data supporting for the use of CO_2 as a contrast agent.