The investigation of the cardiac veins have been neglected for decades because of the great importance of the coronary arteries in the pathogenesis of coronary heart disease. Advances in modern medicine and the introduction of innovative diagnostic and therapeutic procedures have led to the alternative routes to the access of the damaged heart, where the cardiac veins play an important role. Before the application of the new imaging methods for cardiac vessels, only dissection of the hearts were used. Now, with the help of these new diagnostic methods, the different classifications of cardiac veins was present. Most cardiac veins drain into the right atrium. The coronary sinus and its tributaries and the anterior cardiac veins have an important role in collecting and returning blood from the heart has. These veins constitute the greater cardiac venous system, while smaller cardiac venous system consists of the Thebesian vessels. They are the subject of an ongoing research in order to adapt to the different needs of myocardial drainage depending on the age and changes in various heart diseases. Variations of cardiac veins are common. The knowledge of cardiac vein variations and anastomoses have become important for understanding and interpretation of the heart vein images during performing diagnostic and therapeutic procedures.