By way of a quasi-experimental study it was attempted to determine whether motivational interviews as a nursing intervention were effective in promoting self-care amongst patients with heart failure in a fourth-level hospital in Bogotá, between January and May 2012. Two self-care assessments, a base one and a later one after the implementation of motivational interviews and telephone monitoring (15 days after the first assessment) were carried out among a sample of 21 patients. The degree of improvement was then calculated according to the European Heart Failure Self-Care Behaviour Scale (EHFScBS), which considers three categories: compliance with the therapeutic regimen, capability of adaptation to the disease and looking for help when symptoms aggravate. Applying the non-parametrical signed-rank test, which is centred in the median, we obtained a probability of 0.0207 (less than 0.05), and it is thus to be inferred that the motivational interview as a nursing intervention is effective. According to the EHFScBS’ three parameters, a general increase in self-care was observed, from medium to high. Motivational interviews brought the participants to implement activities that favour self-care, which allowed them to determine by themselves what was or was not beneficial to their health.