OBJECTIVES--To improve blood pressure control among hypertensive ( > 140/90 mmHg) excessive alcohol drinkers. DESIGN--Fourteen worksite physicians were randomised onto an intervention group and a control group. The intervention was based on training the worksite physicians and follow up of those hypertensive subjects defined as excessive drinkers. Follow up was based on self monitoring of alcohol consumption by the subject, in view of the results of their gamma glutamyl transferase (GGT) activity determination. SETTING--Fourteen workplaces in France - mainly in the industrial sector. SUBJECTS--Altogether 15 301 subjects were screened by the 14 physicians: 129 of these were included in the study. MAIN OUTCOME MEASURES--This was the difference between the initial systolic blood pressure (SBP) and the SBP one year later (delta BP). Secondary criteria were the difference between the initial and final diastolic blood pressure (delta DBP) and delta BP at two years; antihypertensive treatment; state alcohol consumption (delta AC); delta GGT; and body mass index (delta BMI). RESULTS--The decrease in SBP levels was significantly larger in the intervention group than in the control group: at one year, delta SBP values were -11.9 (15.6) mmHg and -4.6 (13.8) respectively (p < 0.05). This benefit was still observed after two years of follow up (-13.8 (17.4) mmHg v -7.5 (14.2) mmHg (p < 0.05)). No difference was observed in DBP. The percentage of treated subjects did not differ between groups. At one year, delta AC was larger in the intervention group (-2.8 (5.2) U/d) than in the control group (-1.6 (3.4) (p < 0.1)). delta GGT and delta BMI did not differ between the two groups. A weak positive correlation was observed between delta AC and delta SBP (r = 0.16). CONCLUSION--An intervention aimed at the hypertensive excessive drinkers in a working population was found to be effective in reducing SBP on a long term basis (two years). The mechanisms of reduction in alcohol consumption and improved drug compliance cannot be ascertained in this pragmatic study. From a public health point of view, reducing the excess cardiovascular risk among a "hard to reach" population seems feasible with a strategy specifically designed for this high risk group.