BACKGROUND/OBJECTIVES: Mediterranean diet has favorable effects on the cardiovascular system, whereas albuminuria is associated with atherosclerosis progression. The aim of the study was to assess the relationships of adherence rates to the Mediterranean diet with albumin to creatinine ratio (ACR), in a cohort of Greek adolescents who participated in the Leontio Lyceum ALbuminuria (3L) study. SUBJECTS/METHODS: In a total of 365 adolescents 12-17 years of age included in 3L study, ACR values were determined in a morning-spot urine. RESULTS: The Mediterranean diet Quality Index for children and adolescents (KIDMED) was estimated and accordingly subjects were divided into those with high (≥ 8), average (4-7) and low (≤ 3) score. Adolescents with low (n=153, 42%) compared with those with average (n=187, 51.2%) and high (n=25, 6.8%) KIDMED score were characterized by greater ACR values (22.4 vs 13.4 vs 12.1 mg/g, P<0.05) even after adjustment for confounders. In the total population, KIDMED score was related to body mass index (r=0.122, P=0.02), waist circumference (r=0.118, P=0.02), systolic blood pressure (BP) (r=0.119, P=0.023), whereas it was negatively associated with ACR (r=-0.111, P=0.041). Regarding ACR, it was associated with age (r=-0.11, P=0.044), male sex (r=0.16, P=0.003), body mass index (r=-0.131, P=0.016) and systolic BP (r=-0.144, P=0.008). CONCLUSIONS: Adolescents who adhere to the Mediterranean diet exhibit lower levels of albuminuria, independently of demographic and hemodynamic confounders. The inverse relation of KIDMED index with ACR suggests a close link of accelerated vascular damage reflected by albuminuria with low adherence to this favorable diet of the Mediterranean basin.