The potential role of blood pressure and antihypertensive treatment on the progression of advanced chronic renal failure was analyzed in 223 adult patients (126 males) with well-defined primary chronic renal diseases (glomerulonephritis, n = 73; angionephrosclerosis, n = 24; interstitial nephritis, n = 61; polycystic kidney disease, n = 52, Alport's syndrome, n = 13). Effect of average mean arterial pressure (MAP) obtained during follow-up, antihypertensive treatment (normotensive, conventional antihypertensive treatment, angiotensin-converting enzyme inhibitors [ACEI]), gender, type of the nephropathy, age, body mass index, and protein intake were analyzed using a multivariate analysis of variance. Mean arterial pressure was significantly and independently correlated with duration (r = -0.40, P < 0.0001) and slope of creatinine clearance (delta Ccr; r = 0.32, P < 0.0001). Mean arterial pressure and antihypertensive treatment could predict 25% of the variation in duration. Gender, type of the nephropathy, and MAP were able to predict 30% of the variation in delta Ccr. When analyzing results by type of nephropathy, MAP was significantly and inversely correlated with duration in glomerulonephritis (r = 0.29, P < 0.05), and positively with delta Ccr in angionephrosclerosis and interstitial nephritis (r = 0.49, P < 0.05 and r = 0.36, P < 0.01, respectively). In each type of nephropathy, conventional antihypertensive treatment and ACEI had grossly similar effects upon duration and slope except. In conclusion, blood pressure level is an important contributor to progression of chronic renal failure but its effect was more evident in angionephrosclerosis and interstitial nephritis at the extreme values of blood pressure distribution.(ABSTRACT TRUNCATED AT 250 WORDS)