The aim of this study was to compare B-mode and echo tracking methods to assess endothelium-dependent flow-mediated dilation (FMD). Baseline brachial artery diameter, 60-s post cuff release diameter and FMD percent were assessed in 17 normal, healthy individuals using both techniques. Mean values for baseline diameter, 60-s diameter and FMD for M-mode were 3.83 +/- 0.69 mm, 4.06 +/- 0.66 mm and 6.35 +/- 3.98%, respectively. Mean values for baseline diameter, 60-s diameter and FMD for B-mode were 3.75 +/- 0.65 mm, 4.00 +/- 0.63 mm and 6.91 +/- 2.85%, respectively. Results, as displayed by Bland-Altman graphs, indicate a strong agreement between B-mode and echo tracking methods of assessing brachial artery diameter changes via FMD.