Aim. To estimate changes in renal function in patients with acute hypertensive encephalopathy (AHE) during standard inpatient antihypertensive therapy. Subjects and methods. Patients were selected for the trial in the cardiology and admission units of a Perm hospital. The group included 60 patients with AHE. The patients received inpatient antihypertensive therapy for 10-14 days. Within the first 2 hours, enalaprilate 1.25 mg was intravenously injected, by monitoring blood pressure. After 6 hours, the patients were given enalaprilate tablets 20 mg b.i.d. plus hydrochlorothiazide 12.5 mg (Subgroup 1) or nifedipine 60 mg plus hydrochlorothiazide 12.5 mg (Subgroup 2). The laboratory parameters of kidney function were measured twice: on admission to and before discharge from hospital. Plasma creatinine and urea concentrations were estimated. Glomerular filtration rate (GFR) and urea/creatinine ratio were calculated. The patients were found to have proteinurea, low GFR, high plasma creatinine concentrations, and increased urea/creatinine ratio. Results. Transient proteinuria was observed in 25% of the patients with AHE within the first 24 hours of the disease. The proportion of patients with lower GFR was unchanged during a 2-week treatment period (20 and 16%, respectively; p=0.22). There was a rise in the proportion of patients with higher urea/creatinine ratio (83 and 95%, respectively; p=0.006). Conclusion. The course of AHE is complicated by cardiorenal syndrome (CRS) with transient proteinuria and low GFR, as well as by prerenal azotemia (PRA). The number of patients with PRA increased after 2-week conventional inpatient antihypertensive therapy (enalaprilate + hydrochlorothiazide 12.5 mg or nifedipine + hydrochlorothiazide 12.5 mg).