Background: Impaired fasting plasma glucose (IFG) as well as diabetes mellitus (DM) may influence the presence of another metabolic syndrome (MetS) components resulting in the different risk of cardiovascular (CV) morbidity and mortality. This study aimed to determine the impact of IFG as well as DM on the 10-year CV risk using Thai CV risk score and primary prevention in complying with CV risk score in these patients. Methods: This cross-sectional study was conducted at the internal medicine clinic, Pathum Thani Hospital, Thailand. The study was approved by the hospital ethics committee and written informed consent was obtained from all patients. Patients having MetS according to the criteria of the International Diabetes Federation were enrolled while those with a history of CVD were excluded. The 10-year CV risk was assessed using the Thai CV risk score. Results: The total of 112 patients were enrolled in the study. They were in old age and female sex was a significantly higher proportion (61.70% vs 35.50%, P = 0.013). Of these, 72.32% had IFG or DM. Proportions of patients with moderate and high CV risk score were significantly greater in IFG/DM group and only 34.48% and 79.31% of patients with moderate or high CV risk score received aspirin and statin. IFG or DM significantly elevated CV risk score (OR = 6.66, 95% CI = 2.29, 19.58). Conclusions: IFG/DM significantly elevated CV risk score in these patients with the strongest impact. The assessment of CV risk is highly recommended for primary prevention and long-term CVD benefit.