The purpose of the study is determination of predictors of hypertensive nephropathy progression based on of long-term follow-up of essential hypertension (EH) patients with initial decline of kidney function. During five years we performed treatment and follow-up of 57 EH patients with kidney insufficiency. The study consisted of four stages: I – primary inspection, ІІ – treatment with losartan during 12 months, IIІ – treatment under supervision of primary physicians during 48 months, IV – the repeated inspection. The kidney functional state (glomerular filtration rate (GRF)) was determined by endogenous creatinine clearance. One year losartan treatment resulted in the decline of blood pressure and stabilized GFR: during 3 months of treatment GFR remained unchanged (at the beginning 67.4±2.3 ml/min, in 3 months 67.4±3.4 ml/min), in 12 months it diminished to 65.70±3.07 ml/min. At the repeated inspection on the IV stage the level of blood pressure went back to initial values, which coincided with increase of creatinine concentration, considerable and reliable decline of GFR to 54.7±3.5 ml/min. Univariate regression analysis revealed following predictors of kidney function decline: initial GFR, level of pulse pressure and plasma uric acid concentration.