Lifestyle factors like weight, alcohol consumption, salt intake and physical activity have shown to be important in treating hypertension. There have been made some randomised trials about the effects of lifestyle interventions, but the numbers of patients have been relatively small and the durations of follow-ups have been short. No controlled trials assessing the effects of lifestyle intervention in a rehabilitation setting have been reported. In this study, the effects of multidisciplinary lifestyle intervention in rehabilitation centres among middle-aged hypertensive employees were described. A total of 731 hypertensives from 45 worksites were randomised to lifestyle intervention in a rehabilitation centre or to usual care in an occupational or primary health-care centre for 12 months. Standard measurements were conducted before the intervention and 1-year later. Blood pressure (BP) levels were clearly reduced in the intervention group, while only minor changes were observed in the control group. The net changes between the two groups both for systolic and diastolic BPs were -2.1 mmHg (95% confidence intervals (CI) -4.0 to -0.1) and -1.5 mmHg (95% CI -2.6 to -0.4), respectively. The net changes were greater among men than women. The multidisciplinary lifestyle intervention in a rehabilitation centre setting produced significant reductions in BP among middle-aged employees with hypertension.