BACKGROUND: The Global SYMPLICITY Registry DEFINE (Denervation Findings in Real World) investigates radiofrequency renal denervation (RDN) in a broad range of patients with hypertension. We evaluated whether the number or type of antihypertensive medications were associated with increased long-term blood pressure (BP) reductions and cardiovascular outcomes following radiofrequency RDN. METHODS: Patients underwent radiofrequency RDN and were categorized by baseline number (0–3 and ≥4) and different combinations of medication classes. BP changes were compared between groups through 36 months. Individual and composite major adverse cardiovascular events were analyzed. RESULTS: Of 2746 evaluable patients, 18% were prescribed 0 to 3 and 82% prescribed ≥4 classes. At 36 months, office systolic BP significantly decreased ( P <0.0001) by −19.0±28.3 and −16.2±28.6 mm Hg in the 0 to 3 and ≥4 class groups, respectively. Twenty-four–hour mean systolic BP significantly decreased ( P <0.0001) by −10.7±19.7 and −8.9±20.5 mm Hg, respectively. BP reduction was similar between the medication subgroups. Antihypertensive medication classes decreased from 4.6±1.4 to 4.3±1.5 ( P <0.0001). Most decreased (31%) or had no changes (47%) to the number of medications, while 22% increased. The number of baseline antihypertensive medication classes was inversely related to the change in prescribed classes at 36 months ( P <0.001). Cardiovascular event rates were generally low. More patients in the ≥4 compared with 0 to 3 medication classes had myocardial infarction at 36 months (2.8% versus 0.3%; P =0.009). CONCLUSIONS: Radiofrequency RDN reduced BP safely through 36 months, independent of the number and type of baseline antihypertensive medication classes. More patients decreased than increased their number of medications. Radiofrequency RDN is a safe and effective adjunctive therapy regardless of antihypertensive medication regimen. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01534299.