OBJECTIVES: To evaluate in CKD prevalence and prognosis of true resistant hypertension (RH), that is, confirmed by ambulatory blood pressure (ABP) monitoring. BACKGROUND: In CKD, uncontrolled hypertension is a major risk factor but no study has properly investigated the role of RH. METHODS: We prospectively studied 436 hypertensive CKD patients under nephrology care. Four groups were constituted by combining 24h-ABP with diagnosis of RH (office BP ≥130/80 mmHg despite adherence to ≥3 full-dose antihypertensive drugs including a diuretic or ≥4 drugs): control (ABP<125/75 without RH), pseudoresistance (ABP<125/75 with RH), sustained hypertension (ABP≥125/75 without RH), true resistance (ABP≥125/75 with RH). Endpoints of survival analysis were renal (end-stage renal disease or death), and cardiovascular events (fatal and non-fatal cardiovascular event). RESULTS: Age was 65±14 years, males 58%, diabetes 36%, cardiovascular disease 30%, median proteinuria 0.24 (interquartile range 0.09-0.83) g/day, eGFR 43±20 mL/min/1.73m(2), office BP 146±19/82±12 mmHg, 24h-ABP 129±17/72±10 mmHg. True resistant patients were 22.9% and pseudoresistant 7.1%, while patients with sustained hypertension were 42.9% and controls 27.1%. Over 57 months of follow up, 109 cardiovascular events and 165 renal events occurred. Compared to controls, cardiovascular risk [Hazard Ratio, (95% Confidence Interval)] was 1.24 (0.55-2.78) in pseudoresistance, 1.11 (0.67-1.84) in sustained hypertension and 1.98 (1.14-3.43) in true resistance. Corresponding hazards for renal events were 1.18 (0.45-3.13), 2.14 (1.35-3.40) and 2.66 (1.62-4.37). CONCLUSIONS: In CKD, pseudoresistance is not associated with an increased cardio-renal risk and sustained hypertension predicts only renal outcome. True resistance is prevalent and identifies patients carrying the highest cardiovascular risk.