Implantable pulse generators and defibrillators have traditionally been considered contraindications to MRI. However, recent data have challenged this paradigm and demonstrated that patients with newer generation devices can safely undergo MRI, including cardiac MRI, provided basic precautions are taken. Indeed, the introduction of MRI conditional systems has led to a conceptual shift in clinical decision making-'can this patient undergo MRI safely?' is being superseded by 'should this patient be implanted with an MRI conditional device?'. This review outlines the risks associated with MRI in patients with implanted cardiac devices, and discusses practical measures to minimise risks and facilitate safe and diagnostic scanning.