Out of hospital cardiac arrest is generally managed by cardiopulmonary resuscitation (CPR) and defibrillation. The precordial thump can also be used in the initial management of witnessed cardiac arrest whilst awaiting direct current cardioversion. However, complications are associated with a precordial thump. We report a case of an out-of-hospital cardiac arrest due to ventricular fibrillation that was treated initially with a precordial thump, which resulted in a sternal fracture and the development of sternal osteomyelitis.