This paper presents measurements of three-dimensional (3-D) displacements and velocities of the coronary arteries due to the myocardial beating motion and due to breathing. Data were acquired by reconstructing the coronary arteries and their motion from biplane angiograms in 10 patients. A parametric motion model was used to separate the cardiac and breathing motion fields. The arteries move consistently toward the left, inferior, and anterior during a cardiac contraction. The displacement and velocity of the right coronary artery during a cardiac contraction was larger than measured for the left coronary tree. Cardiac motion dominates the respiratory motion of the coronary arteries during spontaneous breathing. On inspiration, the arteries move caudally, but the motion in the left-right and anterior-posterior axes was variable. Spatial variation in respiratory displacement and velocity of the coronary arteries indicates that the breathing motion of the heart is more complex than a 3-D translation.