Breast cancer treatments have evolved over the past decades, although several widely used treatments have adverse cardiac effects. Radiotherapy generally improves the survival of women with breast cancer, although its deleterious cardiovascular effects pose competing risks of morbidity and/or mortality. In the past, radiation-associated cardiovascular disease was a phenomenon considered to take more than a decade to manifest, but newer research suggests that this latency is much shorter. Knowledge of coronary anatomy relative to the distribution of the delivered radiation dose has improved over time, and as a result, techniques have enabled this risk to be decreased. Studies continue to be performed to better understand, prevent and mitigate against radiation-associated cardiovascular disease. Treatments such as anthracyclines, which are a mainstay of chemotherapy for breast cancer, and newer targeted agents such as trastuzumab both have established risks of cardiotoxicity, which can limit their effectiveness and result in increased morbidity and/or mortality. Interest in whether β-blockers, statins and/or angiotensin-converting enzyme (ACE)-inhibitors might have therapeutic and/or preventative effects in these patients is currently increasing. This Review summarizes the incidence, risks and effects of treatment-induced cardiovascular disease in patients with breast cancer and describes strategies that might be used to minimize this risk.