Background The present study was carried out to evaluate the blood pressure (BP)-lowering effect and the safety aspects of Lactobacillus helveticus LBK-16H fermented milk with high tripeptide doses on hypertensive subjects using 24-h ambulatory measurements (ABPM). Methods In a randomized, double blinded placebo-controlled parallel group study, 94 hypertensive patients not receiving any drug treatment were given 150 mL twice daily of either L. helveticus LBK-16H fermented milk with a high concentration of tripeptides (Ile-Pro-Pro 7.5 mg/100 g and Val-Pro-Pro 10 mg/100 g) or a control product, for 10 weeks after a 4-week run-in period. Twenty-four-hour ABPM were taken at the beginning and at the end of the intervention period. The average baseline systolic and diastolic BP values were 132.6 ± 9.9/83.0 ± 8.0 mm Hg in the L. helveticus group and 130.3 ± 9.6 /80.2 ± 7.0 mm Hg in the control group. Results There was a mean difference of −4.1 ± 0.9 mm Hg in systolic ( P = .001) and a −1.8 ± 0.7 mm Hg in diastolic BP ( P = .048) between the L. helveticus group and the control group. There was no difference in the sum of the adverse events ( P = .820). Conclusions Lactobacillus helveticus LBK-16H fermented milk containing bioactive peptides, in daily use, does have a BP-lowering effect in hypertensive subjects and is thus a potential for the dietary treatment of hypertension.