Resistant hypertension (RH) is defined as uncontrolled office blood pressure (BP) in spite of the use of at least three antihypertensive medications. Although its condition has a high prevalence, it is still understudied, and its prognosis is not well established. Some prospective studies evaluated the prognostic value of ambulatory BP monitoring, ECG and renal parameters. They pointed out that ambulatory BPs are important predictors of cardiovascular morbidity and mortality, whereas office BP has no prognostic value. The diagnosis of true RH and the nondipping pattern are also valuable predictors of cardiovascular outcomes. Moreover, several ECG (prolonged ventricular repolarization, serial changes in the strain pattern and left ventricular hypertrophy) and renal parameters (albuminuria and reduced glomerular filtration rate) are also powerful cardiovascular risk markers in RH. These markers and others yet unexplored, such as arterial stiffness and serum biomarkers, may improve cardiovascular risk stratification in these very high-risk patients.