Background and objectives: Low socioeconomic status (SES) is associated with both development and progression of chronic kidney disease (CKD). The impact of SES on severity of CKD at presentation to a renal service is less well known. This study investigated the relationship between SES and severity of CKD in a retrospective, cross-sectional analysis involving 1657 patients at the Sheffield Kidney Institute (Sheffield, UK). Design, setting, participants, & measurements: SES was assigned to each patient according to electoral ward of residence by postcode and ranked according to the corresponding British Index of Multiple Deprivation score, which comprises five deprivation quintiles (Q1, least deprived; Q5, most deprived). National Kidney Foundation Kidney Disease Outcomes Quality Initiative classification of CKD was used for stratification and analysis. Binary logistic regression analysis was applied for the association of variables/risk factors with CKD (lower GFR) at presentation. Results: The age-adjusted prevalence of diagnosed CKD at presentation by area of residence, across the five deprivation quintiles, per million population was Q1 = 1495, Q2 = 3530, Q3 = 3398, Q4 = 3989, and Q5 = 19,599. Logistic regression models showed that living in the lowest SES quintile area (Q5) as compared with the highest SES (Q1) was associated with a greater risk for presenting with a lower estimated GFR, after adjustment for sociodemographic, lifestyle, and clinical variables. Conclusions: Low SES is related to severity of CKD at presentation. Further studies are needed to examine this issue across the various SES categories in the United Kingdom. Chronic kidney disease (CKD) is now a widely recognized public health issue of major importance (1). The progressive nature of CKD, the ensuing ESRD, and associated cardiovascular morbidity and mortality are putting a considerable burden on global health care resources (1). Socioeconomic differentials in health are widely recognized; individuals of lower socioeconomic status (SES) have a higher risk for mortality and morbidity compared with those of higher SES (2,3). Low SES is associated with increased risk for CKD from studies mostly based in the US population (4–10) and a few in Europe (11,12). The association of CKD with SES in the various studies could be related to a higher number of socioeconomically disadvantaged individuals living in an area or the effect of the characteristics of the area (13). A number of reasons warrant this study despite extensive literature on the subject. First, there is still a paucity of data on the relationship between area of residence SES and severity of established CKD at presentation to a renal service in the United Kingdom. Second, the previous works on this topic concentrated mainly on patients with ESRD. Third, differences across regions and countries on the population mix, access and quality of health care, and even lifestyle may have a different impact on the relationship between SES and CKD. The underlying hypothesis in this study, therefore, was whether characteristics of an area of residence, in terms of measures of SES, have an impact on level of kidney function of patients with CKD at presentation. We therefore studied the association between area-level SES and severity of established CKD at presentation to a renal service in the United Kingdom and also examined whether any association is independent of established risk factors for CKD.