Detecting myocardial perfusion reserve differences using blood oxygen level dependent (BOLD) MRI may improve at 3 T vs 1.5 T. Stenosis-model dogs (n=3) were imaged at 3 T using a gradient echo sequence (GRE) with T2-preparation for BOLD weighting and without as a control. 3 short-axis slices were acquired at rest and during stenosis and adenosine-induced stress with fluorescent microspheres injected to provide blood flow information. Quantitative measurements showed significant changes for BOLD images (left anterior descending (LAD) or septal vs left circumflex (LCX) regions=1.20±0.11; LAD vs septal regions=1.03±0.06; p<0.001), but not for control images (LAD or septal vs LCX regions=1.01±0.04; LAD vs septal regions=0.99±0.05; p=0.09). BOLD MR vs microsphere measured flow (MR=0.053*SPHERE+1.03) showed good correlation (R=0.61). In conclusion, 3 T BOLD imaging was able to identify myocardial perfusion changes.