Hydroxychloroquine (HCQ) is a widely used drug to treat patients with coronavirus disease 19 (COVID-19). Although evidence of its efficacy and safety remains limited and controversial, both cardiac and non-cardiac adverse events are known to be associated with its use. To our knowledge, electrical storm in patients with COVID-19, or in any case treated with HCQ, has not been reported. We report the case of a 78-year-old male with an implantable cardiac resynchronization defibrillator (CRT-D) and a non-severe form of COVID-19. After a few days of home therapy with HCQ, an electrical storm was revealed that was associated with an increase in QTc. Following admission to the intensive care unit, HCQ was discontinued and progressive reduction of the QTc with electrical stabilization was observed. This clinical case highlights the potential risk of arrythmia associated with the use of HCQ and stresses the need for close electrocardiographic monitoring, especially in patients with established heart disease.