The number of patients with heart failure is increasing. The purpose of this study was to determine the efficacy of two nursing educational strategies (Personalized Education and Phone Education) to raise the knowledge about the disease in outpatients with heart failure. Controlled clinical trial. Analysis was by intention to treat. 116 patients were randomized. In the group who received personalized educational intervention, the delta score of knowledge increased in the final evaluation at 1.04 (95% CI: 0.94, 1.14), and in the follow‐up at 0.73 (95% CI: 0.63, 0.83). Also, for the group assigned to educational by phone, the delta score of knowledge increased in the final evaluation at 1.00 (95% CI: 0.92, 1.07), and in the follow‐up at 0.73 (95% CI: 0.64, 0.81). Both interventions had a beneficial effect. Nursing education in these patients, regardless of the strategy (personalized or by phone) is useful and therefore nurses should be included in the multidisciplinary teams of care. (Latin American Clinical Trials Register: COL112).