The aim of this study is to get anatomical information on internal mammary vessels in Asians. Cadaver study is very limited in our country due to sociocultural backgrounds. We used two dimensional reconstructive computed tomography (2DCT) and Doppler ultrasound for anatomic study. The branching patterns, level of bifurcation, size of vessels and distance from the sternal edge to the internal mammary vein (IMv) were measured. This study was performed in 60 breast cancer patients from May 1999 to May 2001. Patient's age ranged from 30 to 63 years (average 46). One artery and one vein on both sides were the most common types that were observed in 44 of 60 patients. The diameter of the internal mammary artery (average 2.1 mm) was constant but that of the IMv had a wide variation (ranged 0.8-4.8 mm). The distance from sternum to internal mammary artery gradually decreased as it passed caudally. Compared to Caucasians, in Asians, the cases of IMv bifurcation were fewer. The level of IMv bifurcation was higher than that of Caucasian. The level of choice for anastomosis was 3rd intercostal space in Asians due to their shorter chest. The combination of 2DCT and Doppler ultrasound provided us with a useful preoperative information as well as general anatomical data in Asians. © 2003 The British Association of Plastic Surgeons. Published by Elsevier Ltd. Alt rights reserved.