The aim – to identify patients with true resistant arterial hypertension and to assess patients’ adherence to treatment on the background of a fixed combination of antihypertensive drugs.Materials and methods. 1146 patients with resistant hypertension were included in the study. Men and women over the age of 18 were included, provided that the average level of office blood pressure (BP) was greater than 140/90 mm Hg, when taking 3 or more antihypertensive drugs. Morisky – Green Questionnaire (in a modified scale) (MMAS-8) on patient adherence to treatment. To determine adherence to treatment in some patients, determination of drugs in urine was carried out in the central laboratory. All patients were initially subjected to the following tests: measurement of office SBP, DBP and heart rate, daily monitoring of BP, biochemical blood test.Results and discussion. 51.4 % of patients took 3 antihypertensive drugs. 48.6 % took 4-6 antihypertensive drugs: among them, 4 drugs – 37.1 %, 9.1 % – took 5 drugs, and 2.4 % – 6 drugs. The degree of decrease in office BP among patients taking 3 or more antihypertensive drugs was 43.47 ± 0.65 mm Hg for systolic BP, and 20.33 ± 0.74 mm Hg for diastolic BP (p<0.001 for both values). 355 (31 %) patients failed to achieve the target level of office BP. They had true resistant hypertension. According to the Morisky – Green adherence questionnaire, on the background of the fixed triple combination of valsartan/amlodipine/hydrochlorothiazide, there was a significant improvement in adherence for all questions of the questionnaire. Patients began to forget to take pills significantly less, therapy became stable and regular, there were much fewer cases of stopping taking drugs due to deterioration of the patient’s condition after taking them, all 100 % of patients took antihypertensive drugs on the eve of the visit to the doctor, patients stopped canceling therapy due to their well-being at against the background of treatment, much fewer patients were bothered by the inconvenient regimen of taking drugs. Patient pill size was significant in only 11.4 % of patients at baseline and did not significantly change after 3 months of treatment with the fixed triple combination. But if patients had a choice, 60 % of them would choose the smaller pill. According to the determination of drugs in urine among 12 patients, we found that 25 % of patients (n=3) did not take drugs at all.Conclusions. Resistant arterial hypertension was found in 31 % of patients taking 3 or more antihypertensive drugs. When determining adherence to treatment based on the detection of drugs in urine, 25 % of patients with resistant arterial hypertension did not take the prescribed drugs at all, that is, they had pseudoresistance.