The formation of a fistula between the internal mammary artery and the pulmonary vasculature (IMA-to-PV) is a rare anomaly. The etiology can be congenital; however, most recent cases have been associated with coronary artery bypass grafting, trauma, inflammatory conditions, chronic infections, or neoplasia. The knowledge base on the formation of these fistulas is derived primarily from case reports. To our knowledge, no systematic reviews or guidelines are available that provide information on how to manage these cases, and the treatment of an IMA-to-PV fistula is controversial. To our knowledge, this report is the first to review 80 cases of IMA-to-PV fistulas reported in the literature. We describe the etiologies, clinical presentation, and management of these fistulas.