Background Cavo-atrial avulsion injuries are an extremely rare and life-threatening condition, typically resulting from high-energy trauma. This type of injury is almost always rapidly fatal and is rarely seen due to death of the patient prior to presentation to medical services. Case presentation This case study details the presentation, diagnosis, surgical management, and outcome of an inferior vena cavo-atrial avulsion injury in a 60-year-old male who suffered a fall from height. Initial imaging showed a massive left sided haemothorax without significant signs of injury to the inferior vena cava (IVC). However, Intraoperative findings revealed torrential venous bleeding from an avulsion injury at the level of the inferior cavo-atrial junction. This required cardio-pulmonary bypass, isolation of the right heart and primary repair of the injury. Conclusion IVC avulsion injuries resulting from blunt trauma most commonly occur retro-hepatically due to its relatively fixed position of the IVC, rather than the cavo-atrial junction making such injuries catastrophic in most cases. This report aims to highlight the importance of rapid diagnosis as well as definitive surgical management for this condition. It provides insights into a method of primary repair for this rare type of injury.