Objective: The aim of the present study was to examine serum cystatin C levels in association with the Mediterranean diet in a healthy Greek population. Methods: Cystatin C together with basic clinical chemistry tests was measured in a total of 490 adults (46 ± 16 years, 40% of males), who underwent an annual health check. Demographic, anthropometric and lifestyle characteristics were recorded, while adherence to the Mediterranean diet was evaluated through the MedDietScore (0-55). Results: The mean level of serum cystatin C was 0.84 mg/L, while men had increased serum cystatin C levels compared to women (0.86 mg/L vs. 0.83 mg/L, respectively, 0.017). After adjusting for age, gender, body mass index, smoking status, hypertension, diabetes, hypercholesterolemia, estimated glomerular filtration rate (eGFR), albumin and ferritin levels, each unit increase in MedDietScore led to 0.002 mg/dL drop off in cystatin C serum levels. Conclusions: We have demonstrated an inverse relationship between the MedDietScore and serum cystatin C levels. Our finding that increases in MedDietScore are associated with decreases in serum cystatin C levels could imply that adherence to the Mediterranean diet may reduce the cardiovascular risk, as assessed by cystatin C, a prognostic marker of the cardiometabolic risk. This notion could have a great impact on public health.