To evaluate the influence of treatment on gromerular filtration (GF) in patients with arterial hypertension (AH) and chronic pyelonephritis 51 patients with AH and chronic pyelonephritis were included in 36 month observation. In all patients baseline and at end of study we evaluated office systolic (SBP) and diastolic (DBP) blood pressure (BP); 24-h, daily and night SBP and DBP; GF rate by dynamic renoscintigraphy (Tc99m). All patients were divided on groups: 1st – 44 patients who took chronic antihypertensive treatment; 2nd - 7 patients who took episodic treatment because of their personal reasons. Additionally patients were divided on subgroups in dependency from the base antihypertensive drug: ACE inhibitors, dihydropyridinum calcium channel blockers (CCB), beta-blockers (BB), diuretic (D). In patients of 1st group office SBP and DBP significantly decreased at the end of study from (168,7 +/− 3,4)/(102,3 +/− 2,3) to (136,7 +/− 2,1)/(84,2 +/− 1,8) mmHg (P < 0,001). In the same time, BP in 2nd group increased, but not significant. 24-h, daily and night BP in the 1st group significantly diminished (P < 0,001), but not in the 2nd group. GF rate declined in the both groups, but less in treated patients – from 106,6 +/− 1,9 to 98,9 +/− 2,0 ml/min (P = 0,004) vs from 106,4 +/−5,1 to 87,0 +/− 6,7 ml/min (P = 0,01) in untreated patients. Decreasing of GF correlated not with BP level, but with baseline daily index (R=-0,44, P=0,004 for DI SBP and R=-0,33, P=0,03 for DI DBP): in nondippers lowering of GF was 9,1 ml/min vs 4,8 ml/min in dipper patients. Different renal function impairing was confirmed by increasing of serum creatinine – from 117,8 +/− 1,1 to 128,1 +/− 1,6 μmol/l in the 1st group and from 114,7 +/− 4,7 to 135,0 +/− 5,1* μmol/l in the 2nd gr. (P < 0,001). Patients of CCB and BB subgroup had highest 24-h SBP lowering (on 24,4 and 24,5 mmHg) and less GF rate decreasing (on 7,1 ml/min vs 19,4 ml/min in untreated patients). Patients of ACE inhibitor subgroup had less SBP lowering (on 14,8 mmHg), but almost the same GF rate decreasing – 7,6 ml/min. Effective antihypertensive treatment saved renal function in patients with AH and chronic pyelonephritis. Nondippers had more progressive renal function decline, than dippers. ACE inhibitors had more protected action on GF independently from their antihypertensive effect.