In this pilot study, the authors investigated the preliminary effectiveness of the digital lifestyle intervention, actensio (mementor DE GmbH), in treating arterial hypertension. Adults with arterial hypertension were randomly assigned to an intervention group (actensio + standard care) or a control group (waiting list + standard care) in a 1:1 ratio. Primary and secondary endpoints were assessed at baseline (t0) and 3 months post‐randomization (t1). The primary endpoint was average systolic blood pressure, measured at home for 1 week. Secondary endpoints included patient engagement (measured using the “patient activation measure”; PAM‐13), average diastolic blood pressure, and heart rate. All endpoints were analyzed using ANCOVA models, following an intention‐to‐treat approach, while adjusting for baseline values. Missing data were estimated using multiple imputation models. A total of N = 102 participants (f = 59, age = 52.94 ± 9.01) were randomized to either the intervention (IG; N = 52) or the control group (CG; N = 50), of which N = 80 completed the blood pressure diary, and N = 81 the PAM‐13 at t1. Between‐group comparisons showed an average group difference in systolic blood pressure of −5.06 mm Hg (95% CI = −8.71 to −1.41, p = .013) between the intervention group (M = 137.37 ± 10.13) and the control group (M = 142.35 ± 11.23). Average group difference for patient engagement was 3.35 points with a trend towards statistical significance (95% CI = −018 to 6.89, p = .064), favoring the intervention group (MIG = 79.38 ± 9.44 vs. MCG = 75.45 ± 10.62). There were no group differences in diastolic blood pressure (−1.78 mm Hg; 95% CI = −4.50 to 0.95, p = .402) and heart rate (−0.684; 95% CI = −3.73 to 2.36, p = 0.683). The results of the present pilot study confirm the preliminary effectiveness of the digital lifestyle intervention, actensio, in reducing high blood pressure in patients with hypertension.