Introduction. The use of an implantable cardioverter-defibrillator reduces the probability of sudden cardiac death in patients with heart failure. Objective. To determine the cost-utility relationship of an implantable cardioverter-defibrillator compared to optimal pharmacological therapy for ischemic or non-ischemic NYHA II-III heart failure patients in Colombia. Materials and methods. A Markov model was developed. The model includes costs, effectiveness and quality of life from the perspective of the Colombian health system. For the baseline case, a time horizon of 10 years and discount rates of 3% for costs and 3.5% for benefits were adopted. The transition probabilities were obtained from a systematic review of the literature. The outcome used was the quality-adjusted life years. Consulting with the manufacturers of the device offered in the Colombian market, and using national-level pricing manuals, costs were calculated. Probabilistic and deterministic sensitivity analyses were conducted. Results. In the base case, the incremental cost-effectiveness ratio for the implantable cardioverter-defibrillator was 13,187 USD per quality-adjusted life year gained. For a willingness-to-pay equivalent to three times the gross domestic product per capita as a reference (19,139 USD in 2017), the device is a cost-effective strategy for the Colombian health system. However, the result is sensitive to changes in the time horizon, the probability of death and the device price. Conclusions. The use of an implantable cardioverter-defibrillator for preventing sudden cardiac death in patients with heart failure is a cost-effective strategy for Colombia. The results should be examined considering the uncertainty.