Patients with diabetes mellitus and hypertension are at high risk of vascular complications, particularly, renal deterioration. This study aimed to evaluate the prevalence and the risk factors of reduced renal function corresponding to chronic kidney disease (CKD) stages 3 – 5 among diabetic hypertensive patients. This is a retrospective cohort study of diabetic hypertensive patients attending A-Watani governmental medical center from August 2006 until August 2007. Creatinine clearance (CrCl) was estimated using the Cockcroft–Gault equation. Those with CrCl< 60 ml/ min, corresponding to CDK stages 3 – 5, were considered to have reduced renal function. The prevalence of reduced renal function was calculated, and the risk factors associated with it were evaluated using multiple logistic regression. The following were the results found in this study: (a) the prevalence of reduced renal function among the study patients was 35.5% distributed as follows: (63.5%) had stage 3 CKD, 21.7% had stage 4 and 13% had stage 5 CKD. (b) Patients with reduced renal function were elderly, had a higher number of chronic diseases and had a longer duration of diabetes and hypertension than those with CrCl≥ 60ml/ min. (c) Men had a higher prevalence of reduced renal function than women. (d) Significant predictors of reduced renal function were older age, duration of diabetes and the number of chronic diseases based on logistic regression analysis. Early and continuous screening of renal function among diabetic hypertensive patients is required to implement preventable strategies of end stage renal disease (ESRD). Better control of blood pressure and diabetes mellitus are important.