The purpose of this study was to examine the effects of aerobic exercise on resting systolic and diastolic blood pressure in normotensive adults. The results of nine studies published in journals (1963 to 1992) and representing a total of 438 subjects (289 exercise, 149 control) were statistically aggregated using the meta-analytic technique. Statistically significant reductions were found for both resting systolic and diastolic blood pressure (mean +/- SD, systolic, 3 +/- 3, 95% confidence interval, 1.30 to 5.11; diastolic, 3 +/- 4, 95% confidence interval, 0.05 to 4.82). None of the changes were significant for the control groups. Absolute reductions corresponded with decreases of approximately 2% in resting systolic pressure and 4% in diastolic blood pressure. Significant correlations were found between changes in resting blood pressure and duration of training (systolic, r = .66; diastolic, r = .80, both at P < .05). The results of this study suggest that aerobic exercise results in small reductions on resting systolic and diastolic blood pressure among normotensive adults. However, such small reductions may not be clinically important. In addition, more meticulous studies on this topic are needed.