Objective: To evaluate the usefulness of the diagnostic tests recommended by the European Society of Hypertension/Cardiology Guidelines (ESH-ESC 2007) in hypertensive patients classified as being at low or moderate risk, analyzing the change to high risk classification and the characteristics associated with such change. Methods: A cross-sectional study was made in 391 patients aged between 30 and 80 years recently diagnosed with arterial hypertension in the Primary Care setting. The criteria of the 2007 ESH-ESC Guidelines were followed for the evaluation of risk factors, subclinical organ damage, cardiovascular disease and cardiovascular risk. In addition to the routine tests, echocardiography, carotid ultrasound, albumin/creatinine ratio, estimated glomerular filtration rate, ankle-brachial index, pulse wave velocity and retinography were used. We established four levels of testing performed for risk classification. Results: Using the routine tests to evaluate risk (level 1), 218 (55.8%) patients were classified as being at high risk. Of the 173 patients classified as presenting low or moderate risk, the ankle-brachial index, albumin/creatinine ratio and glomerular filtration rate were determined (level 2), and 18 patients (10.4%) were classified as being at high risk. With echocardiography and carotid ultrasound (level 3), another 16 patients (10%) were raised to high risk. Finally, with pulse wave velocity and retinography (level 4), 10 additional patients (5%) were classified as presenting high risk. Patients with increased blood pressure, advanced age and women showed a 4.28-fold (95%CI: 2.01–9.16), 3.54-fold (95%CI: 1.61–7.77) and 1.36-fold (95%CI: 0.62–3.00) higher probability of being reclassified to high cardiovascular risk, respectively. Conclusions: With the non-routine tests, 25.4% of the low or moderate risk patients were reclassified as presenting high risk.