The purpose of the study was to evaluate in which phase of the cardiac cycle visualization of the cardiac veins could achieve the highest possible quality. In 138 patients (aged 56.6 ± 10.6; 58F) with a suspicion of CAD, a 64-slice CT (Toshiba Aquilion) was performed. In each case ten 3D volume rendering reconstructions were created from 0 to 90% R–R intervals (step 10%) using a 0.5 mm slice thickness (reconstructions 2.0 mm). An arbitrary score of the quality of images was introduced. In 82 (59.4%) patients optimal image quality was noted at the 40% phase, in 28 (20.3%) at the 30% phase and finally in 14 (10.1%) at the 50% phase. These 3 phases (30/40/50%) were the best option for 124 (89.8% of all) patients. In the rest of the patients the best visualization was obtained in other phases as follows: 60 and 80% for 4 patients (2.9%); 70% for 3 patients (2.3%) and at the 0, 10, 20% one patient at each phase (0.7%). The optimal phases of the cardiac cycle for the visualization of the cardiac venous system are 30 or 40%. Less frequently, an alternative could be the 50% phase.