To evaluate the appropriateness of commercial guideline in selecting the size of balloon for intraaortic counterpulsation in Asian patients, we analyzed the relationship between aortic dimensions measured from computed tomography and body indexes. There were 125 patients who underwent the computed tomography. They were divided into three height groups [<152 cm (I), 152-162 cm (II), and 163-183 cm (III)]. Aortic length and diameter were obtained from the origin of left subclavian artery to the orifice of renal artery. We compared those measurements with the balloon size according to the commercial guideline. Aortic lengths were measured as 250 +/- 15 (233-289), 262 +/-16 (227-298), and 285 +/- 19 (239-334) mm in each group, respectively. As the guideline, if we insert the balloon of 25 ml/191 mm, 34 ml/236 mm, and 40 ml/280 mm, there will be 29 of 66 patients (44%) in group III, who have shorter aortic length, with increased risk of obstructing renal artery. In addition, the younger the patient the higher is the risk (p = 0.038). We should pay attention to proper positioning of intraaortic balloon in younger Asian patients with 163-183 cm height, in applying the commercial guideline to prevent renal arterial obstruction.