PURPOSE OF REVIEW: As the percentage of patients achieving long-term survival following treatment of their cancer grows, it is increasingly important to understand the long-term toxicities of cancer-directed treatment. In this review, we highlight the recent findings regarding radiation-induced cardiotoxicity across multiple disease sites, with a particular focus on heart failure. RECENT FINDINGS: Despite its relative lack of study historically, radiation-induced heart failure has now recently been implicated in several studies of breast cancer, lung cancer, esophageal cancer, and lymphoma as a non-trivial potential consequence of thoracic radiotherapy. Data regarding specific cardiac dosimetric endpoints relevant to cardiotoxicity continue to accumulate. Radiation-induced heart failure is a rare but significant toxicity of thoracic radiotherapy, that is likely underreported. Important areas for future focus include understanding the interplay between thoracic radiotherapy and concurrent cardiotoxic systemic therapy as well as development of potential mitigation strategies and novel therapeutics.