Breast artifact occurrence during <sup>201</sup>T1 myocardial image interpretation is a significant problem. We serially evaluated 3 female patients utilizing exercise treadmill perfusion studies in order to assess the potential role of <sup>99m</sup>Tc-Sestamibi (MIBI) imaging in the setting of documented <sup>201</sup>T1 breast artifact. Both visual and quantitative analyses revealed no superiority of <sup>99m</sup>Tc-MIBI over <sup>201</sup>T1 imaging in reference to avoidance of breast artifact. The variation in artifactual cardiac imaging defects in the 3 patients most probably reflected variations in breast positioning. Finally, the ability to assess ventricular wall motion via gated <sup>99m</sup>Tc-MIBI imaging may help to confirm an artifactual versus an actual myocardial perfusion abnormality.