The aim of the study was to assess the clinical value of blood pressure response to stress tests and to study its relationship with ambulatory blood pressure monitoring, daily blood pressure variability and hypertensive complications. Cold pressor test for 2 min, hand grip test at 25% of maximal voluntary contraction for 5 min and orthostatism were performed in 223 young men found hypertensive (BP systolic > 140 mmHg and/or diastolic > 90 mmHg) at the military service recruitment check-up. On the basis of ECG and fundoscopic examination, each patient was attributed a score of target organ damage. All patients underwent non-invasive 24-h blood pressure monitoring and 169 patients underwent echocardiographic examination. Hypertension was confirmed in 54.2% of the subjects at ambulatory monitoring. No correlation was found between blood pressure response to stress tests and ambulatory blood pressure, daily blood pressure variability, target organ damage and left ventricular mass. Night-time ambulatory blood pressure were correlated with posterior wall thickness/ventricular diastolic internal diameter ratio (r = 0.26, P < 0.001). A negative correlation was found between the office-daytime blood pressure difference and systolic and diastolic response to orthostatic test (r = -0.309, P < 0.0001 for systolic blood pressure and r = -0.433, P < 0.0001 for diastolic blood pressure) and between supine office blood pressure and blood pressure response to orthostatism (r = -0.186. P = 0.013 for systolic blood pressure and r = -0.442, P < 0.0001 for diastolic blood pressure).(ABSTRACT TRUNCATED AT 250 WORDS)