The aim of this study was to determine whether the management of hypertension differs between siblings of myocardial infarction patients and the general population. Siblings aged 35 to 74 years, unaffected by myocardial infarction, were drawn from the Augsburg Family Heart Study, conducted in 1996-1997 in southern Germany (n = 524). The reference group consisted of participants of the third MONICA population-based survey conducted in 1994-1995 in the same area, who were aged 35 to 74 years and also unaffected by myocardial infarction (n = 3802). Prevalence, awareness, treatment and control of hypertension (defined by blood pressure > or = 140/90 mm Hg or use of antihypertensive medication) were compared between the two groups. The result was that the prevalence of hypertension was higher in the siblings (men: age-adjusted OR = 1.31, 95% CI: 0.99-1.75; women: age-adjusted OR = 1.83, 95% CI: 1.39-2.41). Male hypertensive siblings were more often aware and treated for hypertension than male hypertensives of the reference group whereas the level of awareness and treatment was comparable between female hypertensives of the two groups. In both genders, no difference in the degree of control was shown between hypertensives of the two groups. In conclusion the siblings and their physicians should pay more attention to the family history of myocardial infarction in order to improve the management of hypertension in this high risk group.