Abstract Background Patient safety is a global goal. Known risks to patient safety are a challenge however, that challenge is significantly increased when a risk is unknown but exists. It is estimated that 18 million major surgeries in Europe are non-cardiac surgical procedures. Preventable adverse events remain a challenge within healthcare systems worldwide. Potentially life-threatening conditions such as inherited cardiac arrhythmias (ICA) can be triggered by a number of factors during the perioperative phase. Healthcare professionals’ lack of knowledge, awareness or confidence about risks associated with ICAs during non-cardiac surgical procedures may have an impact on patient safety and quality of care for people with an ICA. Purpose To determine the knowledge and experience of ICA by healthcare professionals, their views towards and confidence in caring for a person with an ICA in a surgical environment. Method A multiple method study using a twenty-four-item questionnaire was distributed to registered nurses and midwives, surgeons and anaesthetists within surgical areas of seventeen hospitals in the Republic of Ireland and Northern Ireland of which 154 were returned and nine qualitative face to face interviews with registered nurses, midwives, and anaesthetists within surgical areas of one hospital in the Republic of Ireland and one hospital in Northern Ireland. Results Triangulation and convergence of data found a lack of knowledge in relation to inherited cardiac arrhythmias the study focused on, Long QT syndrome, Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) and Brugada syndrome. Within this, it was reported that 88.4% of participants were not aware of the drugs to avoid lists. Of those who were aware, 11.6%, no surgeon reported being aware of the drugs to avoid lists. It was also reported that participants had no confidence to care for people with an ICA in surgical settings. Years since graduation did not equate to an increase in confidence to care for these conditions. Participants reported reliance on the anaesthetist to be knowledgeable, manage care or take the lead should an adverse event occur. However, only seven of the nineteen anaesthetists who took part were aware of the drugs to avoid lists for ICA. Conclusions This study has found a lack of knowledge and confidence relating to inherited cardiac arrhythmias in surgical settings. It also highlighted that anaesthetists are seen as the professional to go to, however they may be unaware of this. Many surgeries take place globally which have the potential to induce an adverse event in people with an ICA that may result in death. This study has found an unknown blind spot which is a serious patient safety issue and a hazardous medical risk factor.