The aim of the research was to study kidney function in association with blood pressure (BP) level and serum uric acid concentration in essential hypertensive (EH) patients under long-term losartan treatment. Fifty seven EH patients with decline of kidney function were included into 6-years prospective study. The predictors of hypertensive nephropathy progression were detected, i.e. glomerular filtration rate, pulse blood pressure and uric acid levels. Losartan therapy contributed to slowing of renal impairment progression. This positive effect was observed even after a period of ineffective BP control. The decrease of serum uric acid concentration under losartan treatment was associated with increase of the glomerular filtration rate, it might have an additional value for nephroprotection in EH patients.