The objective of this randomized controlled trial is to evaluate the benefits of mindfulness meditation in controlling ambulatory blood pressure (BP) and the impact of the intervention on anxiety, stress and depression levels in a Mediterranean population. Twenty-four and 18 patients [n = 42; mean age 56.5 (7.7) years; similar men and women proportions] with high-normal BP or grade I hypertension were enrolled to an intervention and a control group, respectively. For 2 h/week over 8 weeks, the intervention group received mindfulness training and the control group attended health education talks. The patients attended pre-intervention, week 4, week 8 and week 20 follow-up visits. 61.9% of the patients had anxiety, 21.4% depression, 19.0% were smokers and 14.2% were diabetic (no significant differences between the 2 groups). At baseline, the intervention group had non-significant higher clinically measured BP values, whereas both groups had similar ambulatory BP monitoring (ABPM) values. At week 8, the intervention group had statistically significant lower ABPM scores than the control group (124/77 mmHg vs 126/80 mmHg (p < 0.05) and 108/65 mmHg vs 114/69 mmHg (p < 0.05) for 24-h and night-time systolic BP (SBP), respectively) and also had lower clinically measured SBP values (130 mmHg vs 133 mmHg; p = 0.02). At week 20 (follow-up), means were lower in the intervention group (although not statistically significant). Improvements were observed in the intervention group in terms of being less judgemental, more accepting and less depressed. In conclusion, by week 8 the mindfulness group had lower clinically measured SBP, 24-h SBP, at-rest SBP and diastolic BP values.