<b><i>Background/Aim:</i></b> Fat mass and obesity-associated <i>(FTO)</i> gene polymorphisms have been linked to the risk of obesity and diabetes, two well-recognized risk factors for renal disease. Our aim was to determine whether a common <i>FTO</i> polymorphism was associated with a reduced estimated glomerular filtration rate (eGFR) independently of body mass index (BMI) and type 2 diabetes mellitus (T2DM) in a cohort of elderly individuals from the region of Asturias (Northern Spain; RENASTUR cohort). <b><i>Methods:</i></b> A total of 544 Spanish Caucasians aged 55-85 years were genotyped for the <i>FTO</i> rs9930506 single-nucleotide polymorphism (SNP). Individuals with a previous diagnosis of renal disease were not eligible for the study. The eGFR was calculated with the Modification of Diet in Renal Disease formula, and individuals with an eGFR of <60 ml/min/1.73 m² (n = 91) were considered as having impaired renal function. The effect of alleles and genotypes on BMI, hypertension, diabetes, eGFR and blood lipid values was statistically determined. <b><i>Results:</i></b> The rs9930506 GG genotype was significantly more common in the group with a BMI of >25 (p = 0.03; odds ratio = 2.43; 95% CI: 1.09-5.43). Age and T2DM were significant risk factors for a reduced eGFR, but neither obesity nor the <i>FTO</i> genotypes were associated with a reduced eGFR. <b><i>Conclusion:</i></b> The common <i>FTO</i> rs9930506 polymorphism was a risk factor for overweight and obesity in the RENASTUR cohort. However, this SNP was not associated with other comorbidities of the cardiorenal metabolic syndrome in this population.