Twenty-eight men with borderline hypertension according to the World Health Organization criteria underwent maximal exercise testing, and then were followed for a two year period. The prevalence of abnormal blood pressure behavior during exercise was 53.58% (n = 15). During follow-up established hypertension developed in 63.33% (n = 10) of subjects with an abnormal blood pressure response to exercise, and only in 15% (n = 2) of subjects with normal blood pressure behavior. In predicting established hypertension development in a two year follow-up, maximal exercise testing has the following statistical values: sensitivity = 83.33%, specificity = 68.75%, accuracy = 75%, positive predictive value = 66.66%, negative predictive value = 84.61%.