The objective of this study is to present comprehensive morphological data, almost all of it is new, concerning the venous drainage of the myocardium via the coronary sinus and its related veins. This information is of great significance, not least for the sucessful coronary sinus catheterization and reperfusion of most, or single, cardiac veins.The author presents the three principal cardiac venous systems, the greater (major) cardiac venous, the smaller (minor) cardiac venous system, and the compound venous system. The work concludes with an evaluation of the many anatomical peculiarities and and hindrances with regard to the catheterization of the coronary sinus and the reperfusion of (selected) cardiac veins.