Glomerular hyperfiltration is thought to play an important role in the genesis of diabetic nephropathy. While hyperfiltration is well documented in early Type 1 diabetes, the evidence for hyperfiltration in type 2 diabetes is conflicting. The aim of this study was to find out whether Type 2 hypertensive diabetic patients have hyperfiltration and renal hypertrophy and to asses the effects of an angiotensin converting enzyme (ACE) inhibitor, perindopril, on glomerular filtration rate (GFR), kidney size in hypertensive Type 2 diabetic patients. GFR and kidney size have been studied in 32 Type 2 hypertensive diabetic patients (M:F 16:16, mean age 40.9±1.2 year, mean duration of diabetes 2.6 ± 1.0 month) and 30 normal controls (M:F 15:15, mean age 40. 3 .± 2.5) enrolled into this study. In normal subjects total GFR, right and left kidney sizes (length × width) were 105.3 ± 7.0 ml/min, 101.4±2.3 mm × 55.7±3.8 mm and 102.8±2.1 mm × 52.0 ± 4.2 mm. In diabetic patients total GFR, right and left kidney sizes (length width) were 100.6 ± 7.1 ml/min (p> 0.05), 99.12 ± 1.5 mm × 50.03 ± 1.08 mm (p >0.05) and 101.0 ± 1.4 mm × 47.53 ± 1.2 mm (p>0.05) respectively. Patients were prescribed perindopril for eight months. After perindopril treatment, GFR and kidney size did not change significantly. In conclusion there was no hyperfiltration and renal hypertrophy in Type 2 hypertensive diabetic patients. The lack of glomerular hypertrophy, nephromegaly and hyperfiltration suggests that diabetic glomerulopathy is not always associated with preceding hyperfiltration. As a result of this, perindopril therapy did not change kidney size and glomerular filtration rate