Diabetes is the most common cause of end stage renal disease (ESRD). Previous studies imply that angiotensin converting enzyme inhibitor (ACEI) and angiotensin receptor blocking (ARB) drugs contribute to prevalence of ESRD in diabetes. This study investigates renal preservation in diabetes by intensive insulin therapy. 46 adult diabetes patients, 28 females and 18 males were studied for mean 14.2 months (1.5-115 months). Diabetes was diagnosed by 2-h postprandial glucose of ≥ 200 mg/dL (11.1 mmol/L) and treated by Glargine or detemir insulin administered after breakfast and dinner, with regular insulin by finger-stick glucose 2-h post-meal and bedtime. Blood pressure (BP) was controlled with anti-hypertensive therapy excluding ACEI/ARB drugs. Glucose, serum creatinine (Scr), estimated glomerular filtration rate (eGFR), and glycosylated hemoglobin (HbA₁c) at first and last visits were obtained. BP was recorded in both visits. Results were compared between first and last visits. A paired two-tailed test P < 0.05 was significant. Patients were divided by 2hPP glucose of < or > 11.1 mmol/L. Glucose at last visit was significantly lower (8.4 ± 0.6 mmol/L) than first visit (10.3 ± 0.7 mmol/L) in all patients group associated with significantly reduced Scr in last visit (100.3 ± 5.2 µmol/L) compared to first visit (110.9 ± 7.8 µmol/L). No change in eGFR was noted between first and last visits. Significant reduction of HbA₁c (9.14 ± 0.52 v. 7.60 ± 0.45%, p < 0.0148) was found in less than 11.1 mmol/L group. BPs were normal (< 140/80 mmHg) in both visits in all groups. The paradigm of therapy presented in this study is proven effective in renal preservation in diabetes.