Gestational pyelonephritis (GP) is one of the most frequent and serious diseases of the middle and second half of pregnancy, which complicates about 6% of pregnancies and is one of the leading causes of non-obstetric prenatal hospitalization. The objective: was to improve the treatment of GP with phytopreparation Canephron® N. Materials and methods. The paper provides data from the open, multicentre, prospective, comparative (parallel group) study in 60 pregnant women diagnosed with gestational pyelonephritis, which were divided into two groups 30 subjects each. Patients in the treatment group received antibacterial therapy for 7 days + treatment with standard dosage of medicinal product Canephron® N for 3 months. Patients in the control group received antibiotic therapy alone for 7 days. Results. The average age of pregnant women at the time of diagnosing was 23±6.23 years; it was the first pregnancy for 39 women (65 %). The most common complaints at admission to the in-patient department were as follows: lumbar pain (96.2 %), dysuria (70.2 %), rise in temperature above 38°C (64.4 %). Leukocyturia and bacteriuria were detected in 100 % of cases with prevalence of E. coli in 84.2 % (101 of 120) of cases. By 30 day in GP patients in the treatment group bacteriuria was detected in 2/30 (6.67 %) patients, and in the control group – in 5/30 (16.7 %) patients (p 1: 2 <0.05), by 60 day in the treatment group – 2/30 (6.67 %), in the control group – 8/30 (26.7 %) (p 1: 2 <0.05), respectively, by 90 day – 3/30 (10 %) and 10 (33.3 %), respectively (p 1: 2 <0.05). The disease relapsed in 1 of 30 (3.33 %) GP patients in the treatment group and 3/30 (10 %) patients in the control group (p 1: 2 <0.05) and 3/30 (10 %) patients in the treatment group with CP, and 7/30 (23.3 %) patients in the control group during the follow-up period (p 1: 2 <0.05). Conclusion. The use of the herbal medicinal product Canephron® N in pregnant women with gestational pyelonephritis and in the acute exacerbations of chronic pyelonephritis has shown its high efficacy and undoubted therapeutic and prophylactic effect, good tolerability and decrease in the frequency of relapses of pyelonephritis. Key words: gestational pyelonephritis, pregnancy, Canephron® N, leukocyturia, bacteriuria, urosepsis, kidney, infection, urinary tract.