CHD may ensue from chronic systemic low-grade inflammation. Diet is a modifiable risk factor for both, and its optimisation may reduce post-operative mortality, atrial fibrillation and cognitive decline. In the present study, we investigated the usual dietary intakes of patients undergoing elective coronary artery bypass grafting (CABG), emphasising on food groups and nutrients with putative roles in the inflammatory/anti-inflammatory balance. From November 2012 to April 2013, we approached ninety-three consecutive patients (80 % men) undergoing elective CABG. Of these, fifty-five were finally included (84 % men, median age 69 years; range 46–84 years). The median BMI was 27 (range 18–36) kg/m2. The dietary intake items were fruits (median 181 g/d; range 0–433 g/d), vegetables (median 115 g/d; range 0–303 g/d), dietary fibre (median 22 g/d; range 9–45 g/d), EPA+DHA (median 0·14 g/d; range 0·01–1·06 g/d), vitamin D (median 4·9 μg/d; range 1·9–11·2 μg/d), saturated fat (median 13·1 % of energy (E%); range 9–23 E%) and linoleic acid (LA; median 6·3 E%; range 1·9–11·3 E%). The percentages of patients with dietary intakes below recommendations were 62 % (fruits; recommendation 200 g/d), 87 % (vegetables; recommendation 150–200 g/d), 73 % (dietary fibre; recommendation 30–45 g/d), 91 % (EPA+DHA; recommendation 0·45 g/d), 98 % (vitamin D; recommendation 10–20 μg/d) and 13 % (LA; recommendation 5–10 E%). The percentages of patients with dietary intakes above recommendations were 95 % (saturated fat; recommendation < 10 E%) and 7 % (LA). The dietary intakes of patients proved comparable with the average nutritional intake of the age- and sex-matched healthy Dutch population. These unbalanced pre-operative diets may put them at risk of unfavourable surgical outcomes, since they promote a pro-inflammatory state. We conclude that there is an urgent need for intervention trials aiming at rapid improvement of their diets to reduce peri-operative risks.