OBJECTIVES: To assess the costs savings of using an implantable loop recorder (ILR) compared to current clinical practice in the diagnosis of AF for patients who had suffered a first cryptogenic stroke, from the perspective of a Spanish hospital. METHODS: We calculated the hospital resource utilization in the management of patients after a first event. Based on the ILR sensitivity to diagnose AF in order to avoid a second event, we assumed that patients with an ILR implanted won’t suffer a second event while patients without will. Thereafter, we calculated the resource utilization associated to the management of the second event. All resource utilization such as hospitalization (stroke unit and neurology department), length of stay, pharmacological treatment, tests and others were based on expert opinion. Costs were expressed in Euro 2012.   RESULTS: The cost per patient after a fist event was €258 for the non-ILR strategy vs. €1,838 for the ILR, basically due to the cost of implanting the device. A second event occurring only in the non-implanted patients will cost €7,418. Finally, overall treatment costs were €1,838 for the ILR strategy compared to €7,675 for the non ILR strategy. Therefore, implanting ILR will save up to €5,838 per patient per event avoided.  CONCLUSIONS: The use of the Implantable Loop Recorder (Reveal© XT) in patients who had already suffered a first cryptogenic stroke leads to an earlier diagnosis of atrial fibrillation, avoiding potential recurrences. Preventing a second event represents a cost-saving strategy due to the avoidance of €5,838 per patient per event; therefore, it should be included in the clinical management of patients with a first cryptogenic stroke.