Background The aim of this study was to investigate the impact of vitamin K antagonist (VKA) therapy on coronary artery calcification (CAC) by comparing long-term VKA users with metallic prosthetic valves (MPVs) and VKA-free patients undergoing coronary calcium scoring for cardiovascular (CV) risk stratification. Methods A total of 108 patients (43 VKA users with MPV and 65 gender-, age-, and risk-factor-matched VKA-free patients) were included in the study. CAC was determined via computed tomography (CT) and quantified on the basis of the Agatston score. The VKA group comprised patients who had an MPV for longer than 5 years, which entailed long-term VKA use. Results Long-term VKA users had more calcified coronary arteries compared with the control group (178.1 +/- 278 vs. 61.1 +/- 130.6,p= 0.01). There was no difference between groups in terms of traditional CV risk factors. The mean duration of VKA use was 15 +/- 7 years for the patients with MPV. There was no correlation between the duration of VKA use and mean Agatston score (r= 0.2,p= 0.215). Conclusion With its unique selection of patient groups, our study extends the findings of previous research that long-term VKA use is related to CAC as detected via CT scanning. The longer and more potent VKA regimen required for MPV patients is the primary cause of CAC in this group.