Background and Objectives: Several abnormalities are associated with diabetes and metabolic syndrome. Â The effects of diabetes mellitus (DM) include long-term damage, dysfunction and failure of various organs. Diabetes is the most common cause of kidney failure, accounting for more than 40 percent of new cases. Even when drugs and diet are able to control diabetes, the disease can lead to nephropathy and kidney failure. We conducted this study in order to evaluate kidney function in DM-patients in Al-Jouf area, using e-GFR formula.Patients and Method: Assessment of renal function was done in one hundred diabetes mellitus patients, attending the Prince ABDULLRAHMAN AL SODAIRY Hospital, in Skaka, Al-Jouf area. The parameters studied included glycemia, blood urea, serum and creatinine, age and sex. We have calculated and reported an eGFR using the MDRD formula to assess the DM-effects on renal function.Results: We have found that as glucose level increase, the eGFR decrease i.e. increase the risk factor to Chronic Kidney diseases (CKD). According to sex we observed that males present higher eGFR values than females. We observed that more than half of the patients (55%) falls in CKD stage-2, 16% in stage-1, and 27% in stage-3. It is clear from our result that stage-2 more prevalence among the patients than other stages. According to sex, mostly males exhibit more values than females in all stages.Conclusion: We recommended that laboratories calculate and report an eGFR using the MDRD formula with every request for serum creatinine concentration in adults.