Objective: Educational nursing intervention is a strategy that can be useful for changing behaviours in a person’s health. Hospitalisation for coronary surgery is a valuable opportunity for the nurse to implement the knowledge which aims to promote healthy behaviours and secondarily, prevent coronary and cardiovascular disease, as these continue to be the main causes of death worldwide. The purpose of this study is to evaluate the influence of educational nursing intervention in the promotion of a healthy diet and in the anthropometric values (body mass index and waist perimeter) of people who have undergone coronary surgery.Methods: A quantitative and quasi-experimental study was conducted on a control group (20 participants in each group). The experimental group was submitted to a personalised structured educational intervention during hospitalisation, in the nursing follow-up visit (two to three weeks after surgery) and over the phone (two months after surgery). Each group went through two evaluations: the first before the surgery, and the second three months after the surgery. The instruments used to collect data included: the sociodemographic and clinical characterisation questionnaire and the Eating Habits Scale. Non-parametric tests were used.Results: The findings showed that 77.5% of the participants were male and 22.5% female. The participants’ average age was 67.35 ± 8.151. Results showed a significant improvement in the eating habits of both groups, with higher relevance in the experimental group and a reduction of the body mass index and waist perimeter exclusively in the experimental group.Conclusions: Regarding people who have undergone coronary surgery, personalised structured educational nursing intervention is a useful tool in obtaining health benefits and in secondary prevention of cardiovascular disease. More extensive and comprehensive studies are recommended to verify the results and enhance their success.