BACKGROUND Right atrial appendage rupture from blunt trauma is exceedingly rare, even more so when no other chest wall injuries are found. Very few cases have been documented with respect to survival from such an injury. OBJECTIVE To highlight the optimal management of such cases, namely through timely and safe transport to a trauma centre, maintaining a high degree of clinical suspicion for tamponade, early diagnostic ultrasound use, pericardial decompression, haemorrhage control and situational control. METHODS A case report delineating the diagnostic and therapeutic approach to an individual with right atrial appendage rupture. Subsequent post-operative and convalescent course till hospital discharge.A young male patient involved in a high-speed motor vehicle accident was hypotensive at the scene with altered sensorium. Transport to a trauma centre was delayed due to entrapment and geographical location. An ultrasound done on arrival identified cardiac tamponade, which was successfully treated with an emergent left lateral thoracotomy, pericardial decompression, and haemorrhage control from a ruptured right atrial appendage, with definitive closure in the operating theatre. CONCLUSIONS Whilst rare, haemodynamic compromise in the absence of obvious thoracic trauma following high-energy, rapid deceleration mechanisms should raise suspicion for right atrial appendage rupture with pericardial tamponade. Aggressive resuscitation, early diagnostic ultrasound use and urgent pericardial decompression are essential in maximising the likelihood of positive outcomes.