Recent advances in chemotherapy have substantially improved the prognosis of cancer patients. However, many anticancer drugs, especially newly developed `molecular-target drugs', such as the anti-HER2 blocking antibody and the anti-vascular endothelial growth factor antibody, have serious cardiovascular side-effects such as heart failure, thromboembolism, severe hypertension and lethal arrhythmia, which interrupt cancer treatment and decrease the patient's quality of life. Despite the increasing clinical significance, cardiologists have not been focusing enough of their attention on this issue. The major cardiovascular complications associated with anticancer drugs, and current diagnosis, treatment and prevention strategies are reviewed. Close collaborations between oncologists and cardiologists is necessary to tackle cardiovascular complications and advance cancer treatment.  (Circ J 2010; 74: 1779 - 1786)