Damage to heart cells leading to heart failure is a known complication of well-established cancer therapies including anthracycline antibiotics and radiation therapy, and the cardiovascular complications of these therapies has been controlled in large part through dose limitations and modifications of delivery methods. Recent research into the cellular and molecular mechanisms for the cardiovascular effects of these therapies may lead to other cardioprotective strategies that improve effectiveness of cancer treatments. Newer cancer therapies that have been developed based upon specifically targeting oncogene signaling also have been associated with heart failure. Rapid development of a detailed understanding of how these agents cause cardiac dysfunction promises to improve outcomes in cancer patients, as well as stimulate concepts of cardiovascular homeostasis that will likely accelerate development of cardiovascular therapies.