Since the first description of carbon dioxide (CO(2)) angiography the indications for using CO(2) have been changing and the applications of CO(2) angiography evolving. This review covers the contemporary role of CO(2) angiography. CO(2) angiography can be considered according to whether it is likely to be better, equivalent to or worse than conventional iodinated contrast medium (ICM). Areas where CO(2) angiography offers distinct advantages over ICM will be emphasized. The limitations to using CO(2) and specific caveats will be discussed. The basic physical properties of CO(2) and avoidance of the complications of gas angiography will be considered. CO(2) gas is cheap, non-allergenic, and is not nephrotoxic. Unfortunately it is not a panacea, angiographic quality is reduced, it is not tolerated by every patient, and it cannot be used in every location. It is important to be pragmatic and to use conventional contrast or alternative imaging rather than struggling with suboptimal CO(2) angiography.