The purpose of this study was to examine the effect of aerobic exercise on ambulatory systolic and diastolic blood pressure (BP). The results of seven human exercise training studies published in English‐language journals from 1989 to 1993 and representing 12 exercise groups, nine control groups, and a total of 167 subjects were statistically aggregated using the meta‐analytic approach. With outliers deleted from the model, small changes were found among all groups and categories. However, only a change in ambulatory diastolic BP during 24 hours was significantly different from zero. Ambulatory systolic and diastolic BP recorded throughout 24 hours decreased by 1.72 ± 1.80 mmHg (95% confidence interval, 3.10 to 0.34) and 2.56 ± 1.95 mmHg (95% confidence interval, 4.01 to 1.06), respectively. During the waking hours, ambulatory systolic and diastolic BP decreased by 1.25 ± 4.25 mmHg (95% confidence interval, 4.80 to ‐2.30) and 1.32 ± 2.66 mmHg (95% confidence interval, 3.54 to ‐0.90), respectively. A decrease of 1.76 ± 3.44 mmHg (95% confidence interval, 4.94 to ‐1.42) and 3.04 ± 3.01 mmHg (95% confidence interval, 5.82 to 0.26) was observed for ambulatory systolic and diastolic BP during the sleeping hours. A bootstrap simulation (10,000 repeat random samples from the data base), corrected for bias, confirmed the reliability for all original estimates except the change in ambulatory diastolic BP during the sleeping hours (95% confidence interval, 5.27 to 1.29 mmHg). The results of this study suggest that aerobic exercise results in a statistically significant reduction in ambulatory diastolic BP averaged both through 24 hours and throughout sleeping hours. However, a need exists for additional, well‐designed studies on this topic