Adjuvant systemic therapies for the treatment of earlystage breast cancer (EBC) effectively treat the tumor and significantly decrease the risk for recurrence. However, some of these treatments are associated with an increased risk of cardiovascular adverse events. Cardiovascular complications related to cancer therapy may be a prominent concern in postmenopausal women with existing cardiovascular disease or in those who are at high risk for developing cardiovascular disease. The increased risk for cardiac toxicity in women receiving radiation, anthracyclines, and/or trastuzumab for the adjuvant treatment of EBC is well established. The risk of thromboembolic disease is higher in patients with estrogen receptor-positive EBC receiving tamoxifen in the adjuvant setting, whether it is given before or instead of an aromatase inhibitor. In addition, while available data suggest no substantial differences in the risk for ischemic cardiovascular events between aromatase inhibitors and tamoxifen, investigation is still ongoing. Based on this information, it is important for health care providers to understand the cardiovascular risks of treatment and how to monitor at-risk patients, particularly when multiple agents are used in combination or in succession. Improving cardiovascular outcomes in patients with EBC requires cardiovascular risk assessment, management, and long-term follow-up care. Because of the multimodal treatment of EBC patients, their care requires a multidisciplinary approach to reduce not only the risk for breast cancer recurrence but also the risk for treatment-related cardiac toxicities.