The aim of this study was to determine the prevalence and profile of renal artery stenosis (RAS) in NIDDM population with severe hypertension. 60 consecutive NIDDM with severe HT (> or = 3 hypotensive drugs), 42 F/18 M (SR: 2.8), mean age: 66.6 +/- 6.5 years, diabetes duration: 14.1 +/- 6 years have had metabolic, ABPM and renal investigations: color duplex scan (CDS) (with renal us): n = 60, and/or arteriography: n = 17). 13 (21.5%) renal artery stenosis > or = 70%: 8 unilateral/5 bilateral were proved by arteriography. We compared classic HT (n = 47) versus renovascular HT (n = 13). There was no difference for age (years): 64.8 +/- 8 versus 70.6 +/- 6.4, HT duration (years): 11.6 +/- 6.8 versus 12.3 +/- 6. B.M.I.: 31.5 +/- 6 versus 27.6 +/- 3.3, HBA1C (%): 8.9 +/- 2.2 versus 8.8 +/- 0.9, cholesterol (mmol/L): 5.7 +/- 1.3 versus 5.5 +/- 0.6. Significant difference (p < 0.05) was noticed for S.R. (F/M): 2.9 versus 1.16, diabetes duration (years): 11.7 +/- 5 versus 16.5 +/- 8, frequency of retinopathy (%): 30 versus 61, smoking (%): 10 versus 40, triglycerides (mmol/L): 1.9 +/- 1.1 versus 2.6 +/- 1.1, and (p < 0.01) for blood pressure level (mmHg) (SBP: 142 +/- 20 vs 155 +/- 7, DBP: 81 +/- 13 vs 87 +/- 10, MBP: 103 +/- 16 vs 111 +/- 6), frequency (%) of HT escape (> or = 140/SBP, > or = 90/DBP) on ABPM: 40 versus 75 and 24 versus 40, insulin requirence (%): 36 versus 69, macroangiopathy (%): 51 versus 100 (coronaropathy: 34 vs 61, legs arteritis: 21 vs 69, carotid stenosis: 17 vs 30) and for renal function: frequency (%) of micro-macroalbuminuria: 36 versus 92 creatinaemia (mmol/L): 80 +/- 24 versus 124 +/- 44, creatinaemia clearance (mmL/min): 65 +/- 30 versus 40 +/- 12 while are found 5 renal insufficiencies (> or = 120 mmol/L). In NIDDM population with severe HT, renovascular HT is frequent (21.5%), and RAS must be evocated in unstable HT and/or renal injury with macro angiopathy, old NIDDM (> 15 years), requiring insulin. Colour duplex scan (+ renal US) mays lead to arteriography to confirm renal artery stenosis.